Wikipedia talk:WikiProject Mathematics/Archive/2020

Jan 2020

Douglas Ulmer

Eyes and input would be appreciated here. Short version: COI edits at a page that survived AfD as a "no consensus" back in 2017. XOR'easter (talk) 22:45, 3 January 2020 (UTC)

Gleason's theorem nominated for Good Article status

I've nominated Gleason's theorem for Good Article status, because after a few episodes of improvements, I've run out of ideas for further ones. XOR'easter (talk) 18:02, 4 January 2020 (UTC)

You are missing the fact that there is now also a pretty elementary proof of Gleasons' theorem due to Keane and others. https://www.researchgate.net/publication/231919294_An_elementary_proof_of_Gleason's_theorem Richard Gill (talk) 06:34, 5 January 2020 (UTC)

As I mentioned over at the Talk page, I had thought that was already in the reference list at least. Thanks for noticing the omission; it is referenced and used now. XOR'easter (talk) 16:49, 5 January 2020 (UTC)

I will begin a review soon; other reviewers are most welcome! Jakob.scholbach (talk) 20:21, 6 January 2020 (UTC)

Russell's paradox redirects

Please comment on the following set of redirects for discussion: Wikipedia:Redirects for discussion/Log/2020 January 6#Several redirects to Russell's paradox —Naddruf (talk ~ contribs) 19:16, 6 January 2020 (UTC)

Which leads to the question of what to do with Principle of comprehension, which also redirects to Russell's paradox, but is not mentioned there. Perhaps it should be re-redirected to Axiom schema of specification#Unrestricted comprehension, instead. I'd do it myself, but I am an expert, and I may be missing a popular use which should be redirected elsewhere. — Arthur Rubin (talk) 23:41, 6 January 2020 (UTC)

Inverse Pythagorean theorem

I have created a new article titled Inverse Pythagorean theorem. I'm not sure it's worth a separate article, but if so it needs more work. It's severely stubby in its present form. Michael Hardy (talk) 00:19, 30 December 2019 (UTC)

Worth it, I think. One could include a proof, history/origins of the idea, applications, etc. to flesh it out a bit more. Jordan Mitchell Barrett (talk) 07:26, 7 January 2020 (UTC)

Citation oddity

In Cartan connection, a citation was given as

• Cartan, Élie (1926), "Espaces à connexion affine, projective et conforme", Acta Mathematica, 48: 1–42, doi:10.1007/BF02629755.

However, upon inspection, following that DOI, it seems

• Cartan, Élie (1926), "Les groupes d'holonomie des espaces généralisés", Acta Mathematica, 48 (1–2): 1–42, doi:10.1007/BF02629755.

is really what is being cited.

However, in the literature out there, everyone seems to be citing this as the first version. What's going on here? Headbomb {t · c · p · b} 15:43, 6 January 2020 (UTC)

The latter title appears to have more GS citations than the former, 136 to 17. Looking quickly over those 17, they include some pretty dubious items, like 3 by M. S. El Naschie. My guess is that the title was written incorrectly in one place and then carelessly copied into others. XOR'easter (talk) 17:36, 6 January 2020 (UTC)

I'd say that's a plausible scenario. Either way, it's the second version in the article now. Headbomb {t · c · p · b} 18:49, 6 January 2020 (UTC)

Outside of WP articles, the main source of this first mistaken title seems to be the Springer Encyclopedia of Mathematics, e.g., search for the title in the the reference list at [1]. --{{u|Mark viking}} {Talk} 19:37, 6 January 2020 (UTC)

The origin lies in the fact that there is a (Russian translated) collected works of Cartan published by Kazan University in 1962 under the title "Affine, Projective, and Conformal Connection Spaces". — MarkH₂₁^talk 08:00, 7 January 2020 (UTC)

Interesting! I had been wondering if the paper had maybe been included under a different title in a collection. XOR'easter (talk) 14:36, 7 January 2020 (UTC)

Draft:Fraïssé limit

A review is requested of whether this draft should be accepted as a separate article. Robert McClenon (talk) 10:34, 1 January 2020 (UTC)

To clarify: Draft:Fraïssé limit contains all the content of Fraïssé's theorem and Age (model theory), so if it is accepted, those two articles can be deleted and redirected to it. --Jordan Mitchell Barrett (talk) 07:21, 7 January 2020 (UTC)

Thank you, User:D.Lazard and User:Michael Hardy. Edits have been requested. The draft is about mathematics, and I have forgotten more math than most people have learned. Robert McClenon (talk) 20:06, 7 January 2020 (UTC)

I have accepted the draft. I am leaving the previous articles so that the proposal to merge can continue being discussed. Robert McClenon (talk) 05:58, 8 January 2020 (UTC)

Merger proposal: Glossary of module theory -> Glossary of ring theory

Dear all. I have made a proposal that we merge "glossary of module theory" into "glossary of ring theory" (and rename the latter to "glossary of ring and module theory") at Talk:Glossary of module theory#Merger proposal: merge with Glossary of ring theory. Interested editors or editors that object to the proposal are invited to participate in the discussion. (This is really the style issue: I personally prefer few but somehow lengthy glossaries but, of course, the others might have a different preference.) -- Taku (talk) 23:57, 27 December 2019 (UTC)

So far, there have been one opposition and no support; accordingly, unless there is a surge?? of new supports, I will withdraw the proposal in a week or so. -- Taku (talk) 00:04, 9 January 2020 (UTC)

Categorization of mathematical functions possibly up for deletion at CfD

I guess some of you might be interested into a CfD discussion regarding multiple categories grouping special functions like trigonometric, hyperbolic, Jacobian and lemniscatic elliptic functions and their inverses:

Wikipedia:Categories for discussion/Log/2019 December 15#Mathematical functions

The actual contents is organized/merged in a number of larger articles with incoming redirects from the actual function names (that is, the English and Latin names as well as common symbolic names) pointing to the corresponding info in them. These redirects are categorized in order to show up in the corresponding categories of the category system.

Some people interpret our guidelines on categories as if redirects would not to be included in categories and only articles should show up in categories (regardless of their title), while others (including myself) think redirects are appropriate to be included in cases such as this one (so that the actual keywords show up in the category system) and that the relevant guidelines explicitly support this particular usage.

Since people interested in mathematics are among those mostly affected by the outcome of this discussion I thought I would let you know. --Matthiaspaul (talk) 01:37, 13 January 2020 (UTC)

Personally, I have doubts about the Latin names being printable redirects or in categories, but that's an RFD question, rather than a CFD question. — Arthur Rubin (talk) 02:15, 13 January 2020 (UTC)

Redirects for discussion on 32767, 32,767, 32767 (number)

There is an RfD on specific numbers at Wikipedia:Redirects for discussion/Log/2020 January 13#32,767. Feel free to participate. — MarkH₂₁^talk 01:58, 13 January 2020 (UTC)

Update: speedy retargeted. — MarkH₂₁^talk 05:04, 13 January 2020 (UTC)

Parallel (operator)

Could someone check the the content of the article Parallel (operator). It says that

the parallel operator has $\infty$ as neutral element and for $a\in {\overline {\mathbb {C} }}$ the number $-a$ as inverse element. Hence $({\overline {\mathbb {C} }},\|)$ is an Abelian group.

It seems for me that the number $-a$ is an inverse element of a only if $a\neq 0$, because $0\|(-0)=0\neq \infty$. Hence only $({\overline {\mathbb {C} }}-\{0\},\|)$ is an Abelian group.

A further remark, a link Series-parallel duality to Parallel (operator) has been added to List of dualities. I don't think the subject belongs to duality (mathematics).--Cbigorgne (talk) 13:03, 12 January 2020 (UTC)

The problem is that the operator is not continuous at (0,0) and is not defined in the article for this value. Thus it is not a group. However, restricted to nonzero values, it is clearly a group, isomorphic to $\mathbb {C}$, through the multiplicative inverse function. D.Lazard (talk) 14:30, 12 January 2020 (UTC)

I have tagged or fixed the main mathematical flaws, which are all a consequence of the fact that $0\|0$ is an indeterminate form, and is therefore not defined. D.Lazard (talk) 18:21, 12 January 2020 (UTC)

Duality of the series and parallel operations corresponds in circuit analysis to duality of series and parallel circuits. Duality of series and parallel circuits can be interpreted as a special case of the duality of planar graphs. And duality of planar graphs, in turn, is closely related to polar reciprocation of polyhedra and, through it, to projective duality. Why would you think all of this should be unrelated to duality (mathematics)? —David Eppstein (talk) 00:37, 15 January 2020 (UTC)

Links to DAB pages

I have collected another batch of articles with math(s)-related links to DAB pages where expert help would be welcome. Seach for "disam" in read mode and for "{d" in edit mode; and if you solve any of these puzzles, remove the {{dn}} tag and post {{done}} here.

• Cyclical monotonicity  Done — MarkH₂₁^talk
• Data hub  Done XOR'easter (talk) 17:14, 18 January 2020 (UTC)
• Difference hierarchy  Done JBL (talk)
• Fermat’s and energy variation principles in field theory  Done XOR'easter (talk) 17:05, 18 January 2020 (UTC)
• Jean-Pierre Ramis  Done JBL (talk)
• List of first-order theories  Done D.Lazard (talk) 12:03, 18 January 2020 (UTC)
• Locality-sensitive hashing  Done XOR'easter (talk) 17:23, 18 January 2020 (UTC)
• Lusin's separation theorem  Done XOR'easter (talk) 17:16, 18 January 2020 (UTC)
• Rigid analytic space  Done — MarkH₂₁^talk
• State space  Done (though maybe someone should check my work) JBL (talk)
• Subdivision surface  Done JBL (talk)
• Suspension (dynamical systems)  Done XOR'easter (talk) 17:23, 18 January 2020 (UTC)
• Tautological one-form  Done — MarkH₂₁^talk
• Tensor reshaping  Done (although this article is worth for AfD ot WP:TNT) D.Lazard (talk) 13:47, 18 January 2020 (UTC)
• Vasiliev equations  Done XOR'easter (talk) 17:05, 18 January 2020 (UTC)
• Zij al-Sindhind

Thanks in advance, Narky Blert (talk) 01:22, 18 January 2020 (UTC)

The case of Zij al-Sindhind looks tricky. I'm not able to figure out which al-Baghdadi is meant from the source provided; this may call for somebody who has more than a casual familiarity with medieval Islamic science. XOR'easter (talk) 17:05, 18 January 2020 (UTC)

If this al-Baghdadi has a Wikipedia article, this can only be Ibn Sa'd becuse for the other entries of Baghdadi (disambiguation), the living dates do not correspond. But I have no way to know whether Ibn Sa'd is the one that is meant. D.Lazard (talk) 17:28, 18 January 2020 (UTC)

I've added Zij al-Sindhind to my Islam bookmarks folder also, in case someone there knows. Narky Blert (talk) 14:47, 19 January 2020 (UTC)

@MarkH21: I've reverted your fix at Cyclical monotonicity -- see my edit summary for explanation. For everyone else, the question is the meaning of "correspondence" in the context of mutli-valued functions. --JBL (talk) 21:37, 20 January 2020 (UTC)

@Joel B. Lewis: Isn't the article about vector-valued functions? It's only multi-valued if you don't think of a vector as a single object. In any case, the phrase seems to be directly copied from these notes, which uses the surjective map symbol. This really seems to mean an ordinary vector-valued function on Rⁿ. — MarkH₂₁^talk 21:53, 20 January 2020 (UTC)

Okay, I did find a definition (pg 3) for "correspondence" as a bona fide function $f:X\rightarrow 2^{Y}$, with no conditions on surjectivity or injectivity. I suppose this is precisely what is described at Multivalued function. I find it to be silly terminology since a "multi-valued function" is still an ordinary "single-valued function" with the right codomain, but oh well I'm not an economist. — MarkH₂₁^talk 22:04, 20 January 2020 (UTC)

Penrose tiling

Penrose tiling, an article that you or your project may be interested in, has been nominated for a community good article reassessment. If you are interested in the discussion, please participate by adding your comments to the reassessment page. If concerns are not addressed during the review period, the good article status may be removed from the article. AIRcorn (talk) 06:42, 19 January 2020 (UTC)

I view this reassessment as the first shot in an attack on mathematics content in Wikipedia and an attack on the principle that Wikipedia should include and encourage articles on technical content. See the somewhat heated discussion at Wikipedia talk:Good article nominations for more. —David Eppstein (talk) 19:08, 20 January 2020 (UTC)

Its not. Its just some regular cleanup I do every so often of old GAs with tags. AIRcorn (talk) 19:25, 21 January 2020 (UTC)

Speaking generally, I have come to the view it might be ok not to summarize the whole article in the lead when the subject matter is technical. Especially lately, the technical template seems to be in use to indicate the lead contains some technical *precisions* which are simply not understandable without background knowledge. I see this is a matter of trade-offs; like in a board game, you need to make a sacrifice for the greater goal. *Precisions* in the lead are something that can be scarified (since non-math editors seems perfectly content to have a in-depth technical discussion in the body). —- Taku (talk) 23:21, 20 January 2020 (UTC)

Upcoming RFC

Please put Wikipedia:Manual of Style/Medicine-related articles/RFC on pharmaceutical drug prices on your watchlists. Don't answer yet (we're still trying to decide whether anything needs to be polished up any more), but I'd really appreciate it if people who know about statistics/databases would plan to share your expertise with us once it opens (hopefully in another day or two). Thanks, WhatamIdoing (talk) 03:14, 22 January 2020 (UTC)

Feb 2020

Universal hyperbolic geometry

Expert input at Wikipedia:Redirects for discussion/Log/2020 February 1#Universal hyperbolic geometry would be welcome. Narky Blert (talk) 00:46, 2 February 2020 (UTC)

Quartic Polynomials in Sums of three cubes.

Resolved

In Sums of three cubes, the statement is made that "However, 1 and 2 are the only numbers with representations that can be parameterized by quartic polynomials in this way.[5]". I don't understand why Quartic (degree 4) is used here. I could see Cubic or Sextic, but not Quartic.Naraht (talk) 19:28, 3 February 2020 (UTC)

Based on the previous paragraph, I suspect what it's going for is that the terms that are being cubed in the parametrizations are all quartic or less. –Deacon Vorbis (carbon • videos) 19:55, 3 February 2020 (UTC)

Yep, and the cited Mordell paper proves the theorem:

The equation x³ + y³ + z³ = n has no solutions with x, y, z as quartic polynomials in a parameter t with rational coefficients unless n = 2a³, or n = a³, where a is a rational number

— MarkH₂₁^talk 20:35, 3 February 2020 (UTC)

Thanx. I'm not even sure I'd be able to follow the proof to that point (I can't see all of Mordell's paper), but thought I'd check and this seemed the right place.Naraht (talk) 21:34, 3 February 2020 (UTC)

No worries, it's some five pages (i.e. everything but the freely-available first page) of calculations and case-checking. Mordell was quite good at that sort of thing! — MarkH₂₁^talk 22:18, 3 February 2020 (UTC)

Clockwise and counterclockwise on the Riemann sphere

The Riemann sphere can be visualized as the complex number plane wrapped around a sphere (by some form of stereographic projection – details are given below).

In this image of the Riemann sphere, going counterclockwise around ${\textstyle -i}$ corresponds to going clockwise around it in the usual way of depicting the plane. Should this reversal of orientation be considered a problem? Michael Hardy (talk) 20:54, 31 January 2020 (UTC)

Right, the sphere is folded so that the inside is the usual plane. It would be better with i and -i switched. (Also the fonts are quite ugly.) --JBL (talk) 23:31, 31 January 2020 (UTC)

@JBL: If you swap i with −i it would no longer be a stereographic projection of Argand's plane onto a sphere. At least not in the most obvious configuration. The resulting sphere would be an image of a stereographic projection to a sphere tangens from 'below', then rotated by 180° around its (real 1) -- (real −1) diameter. I'm afraid it's much harder for average reader to understand the plane-to-sphere correspondence in this case than in the one depicted above. --CiaPan (talk) 23:52, 31 January 2020 (UTC)

@CiaPan: If you swap ${\textstyle 0}$ and ${\textstyle \infty }$ and leave ${\textstyle \pm 1,\,\pm i}$ where they are, then that fixes the reversal-of-orientation problem and if the Argand plane is parallel to the plane containing ${\textstyle \pm 1,\,\pm i}$ and the center of projection is the point labeled ${\textstyle \infty }$ on the sphere, then you still have an ordinary stereogrpahic projection. Michael Hardy (talk) 04:19, 5 February 2020 (UTC)

The biggest problem with the font is that hyphens appear where minus signs should be:

${\begin{aligned}{\text{minus sign: }}&{-i}\\[5pt]{\text{hyphen: }}&{\text{-}}i\end{aligned}}$

Michael Hardy (talk) 06:12, 1 February 2020 (UTC)

@Michael Hardy: Fixed. --CiaPan (talk) 16:04, 3 February 2020 (UTC)

Or instead of interchanging ${\textstyle \pm i}$ one could interchange ${\textstyle 0}$ and ${\textstyle \infty .}$ Michael Hardy (talk) 06:16, 1 February 2020 (UTC)

Idea for new community workspace

Hi. I would like to create some kind of collaborative workspace where coordinators or members of various WikiProjects would gather and provide updates and information on what is going on at each wikiproject, i.e. regarding their latest efforts, projects, and where interested editors can get involved. For those of you at this very active WikiProject, your input would be very helpful, so I wanted to get your input on whether you'd be interested in helping me to make this happen.

we are discussing this proposal right now at:

* Wikipedia:Village pump (proposals)#Idea for new community workspace

Please feel free to let me know what you think of this idea, and please let me know your preference, regarding the options above. if you do not see any need for this idea, that is totally fine. However, I think that the majority of editors lack awareness of where the truly active editing is taking place and at which WikiProjects, and I would like to do whatever I can to help make people more aware of where the activity is, what they can do to help, and also which areas of Wikipedia offer ideas and efforts that might help them in their own editing activities. Please feel free to let me know.

• Would you be interested in an idea of this nature?
• If so, which option below seems most feasible to you?
  • Create a new page/talk page at the existing WikiProject Council, where members of various WikiProject can gather to offer updates, information and ideas on the latest efforts at each of their own WikiProject, such as Wikipedia:WikiProject Council/Town Hall.
  • Create an entirely new WikiProject with an inclusive name such as
    • Wikipedia:WIkiProject Town Hall,
    • Wikipedia:WikiProject Bulletin Board,
    • Wikipedia:WikiProject Water Cooler
  • Create a new collaborative page or forum, but not as a new WIkiProject, i.e. with some name like
    • Wikipedia:Town Hall or
    • Wikipedia:Water Cooler
  • Create a new sub-page in my own userspace, such as User:Sm8900/Town Hall
  • Create a subpage at an umbrella-type WikiProject that already covers a broad topical area, such as Wikipedia:WikiProject History/Town Hall

thanks. --Sm8900 (talk) 19:03, 9 February 2020 (UTC)

Name change: non-standard -> nonstandard

We are discussing here whether to remove the hyphen in nonstandard analysis, in line with most of the current literature on the topic. Please weigh in. --Jordan Mitchell Barrett (talk) 04:54, 14 February 2020 (UTC)

Seems we've reached a consensus to change. If you see any uses of the word "non-standard" in reference to nonstandard analysis or the use of ultrapower methods, please change these to "nonstandard". --Jordan Mitchell Barrett (talk) 06:01, 15 February 2020 (UTC)

Need a bit of help performing the move - I've done the main page and fixed up that page's content, but still need to do this talk page, everything in this category, etc... — Preceding unsigned comment added by Jordan Mitchell Barrett (talk • contribs) 06:48, 15 February 2020 (UTC)

One of your project's articles has been selected for improvement!

Hello, Please note that Length, which is within this project's scope, has been selected as one of Today's articles for improvement. The article was scheduled to appear on Wikipedia's Community portal in the "Today's articles for improvement" section for one week, beginning today. Everyone is encouraged to collaborate to improve the article. Thanks, and happy editing! Delivered by — MusikBot talk 00:05, 17 February 2020 (UTC) on behalf of the TAFI team

Page proposal - homotopy classification of fiber bundles

There should be a page describing the homotopy classification of fiber bundles. This could include the classification of vector bundles, sphere bundles over spheres, and complex line bundles. This topic motivates a lot of other topics in mathematics, such as characteristic classes and stacks. What are people's thoughts? Wundzer (talk) 22:54, 15 February 2020 (UTC)

Isn’t that what a classifying space (or its variant) is for? Do you have a proposed name for the article you’re proposing? —- Taku (talk) 23:07, 15 February 2020 (UTC)

Whoops, this will work. Thanks for the heads up. This section can be deleted. Wundzer (talk) 18:33, 17 February 2020 (UTC)

Matrix representation of tensors

This article is so problematic (in my view) that deletion is warranted, hence the AfD. If someone with better knowledge of this subject can rescue the article, then I'll withdraw my AfD.

I only had a brief exposure to differential geometry, but I firmly believe that the notion that we cannot represent a metric tensor as a matrix when it is a bilinear form on each tangent space instead of a linear transformation thereof is completely wrong, especially absent actual reliable sources for that view. See Wikipedia:Articles for deletion/Matrix representation of tensors for my full argument on that front. Pinging @D.Lazard, Joel B. Lewis, Slawekb, and RDBury: among others.--Jasper Deng (talk) 08:33, 19 February 2020 (UTC)

Draft:Derived Noncommutative Algebraic Geometry

A review of this draft is requested. Should it be accepted into article space? Robert McClenon (talk) 22:47, 10 February 2020 (UTC)

Unsure if it merits its own article at the moment, but merging it to Derived algebraic geometry (which is currently underdeveloped) is a viable option. — MarkH₂₁^talk 00:32, 11 February 2020 (UTC)

I agree the merger is a better option. My Google search tells that this is the derived version of noncommutative algebraic geometry and so merged with that article makes more sense. —- Taku (talk) 07:18, 11 February 2020 (UTC)

Hi everyone, I saw the DNCAG article was rejected because it was labelled as a spinoff of the article on derived algebraic geometry. Although these articles has similar sounding titles, they are distinct subjects. Here's a useful analogy: algebraic geometry is to noncommutative geometry as derived algebraic geometry is to derived noncommutative algebraic geometry. The basic objects considered in these fields are separate. In DNCAG the objects are triangulated categories while in DAG they are derived rings, such as simplicial rings or differential graded algebras. Here's a couple relevant links https://en.wikipedia.org/wiki/Noncommutative_geometry#Noncommutative_affine_and_projective_schemes https://en.wikipedia.org/wiki/Algebraic_geometry Is it fine if I resubmit this article and not have it declined because of the discussed reasons above? Is there anything you'd like me to add to the DAG article to try and differentiate the two subjects even further? Wundzer (talk • contribs) 19:17, 11 February 2020 (UTC)

Also, here are some plans for the article which further differentiates it from the DAG article: It will include discussions of fourier mukai transforms, deformations of FM transforms, deformations of abelian categories, derived categories of singularities and matrix factorizations. Moreover, check out my comments on the talk page of the DAG page. I've listed out some information for how the article could be expanded, without having a full on merger

Wundzer, what do you feel about the merger with Noncommutative algebraic geometry? If I remember right, thinking that a category (or higher one) is a type of noncommuattive space is central to NAG. So, the merger with the article makes more sense. (On the other hand, the merger with the DAG article is very bad idea). If a length becomes an issue, we can always spin-off the DNCAG portion later. -- Taku (talk) 00:57, 13 February 2020 (UTC)

TakuyaMurata, that's not a bad idea, but let's wait a week or so. I'll go ahead and add more to the DNCAG article and then we can make a decision then. I agree they are similar subjects, Rosenberg has a non-commutative geometry based on abelian categories. Moreover, -- User:Wundzer (talk)

Certainly. —- Taku (talk) 23:23, 13 February 2020 (UTC)

I have risen a potential issue with the article title (i.e., not completely sure if DNAG is the common name) at Draft_talk:Derived_noncommutative_algebraic_geometry#Main reference needed. -- Taku (talk) 00:31, 21 February 2020 (UTC)

Hey, does anyone know how to embed tikz diagrams into wikipedia? I want to draw out the diagram for TR4 in https://arxiv.org/pdf/math/0302304.pdf, but using the objects in the construction part of the article.Wundzer (talk) 20:06, 20 February 2020 (UTC)

@Wundzer: You can upload the diagram as an image, since there is no tikz-cd support in WP right now. Instructions are here, just ignore the xy-pic step. — MarkH₂₁^talk 20:46, 20 February 2020 (UTC)

Boris Tsirelson

Some very bad news regarding Boris Tsirelson is at Talk:Boris Tsirelson#Death. An IP has already added the information to the article, citing the talk page as a reference. This needs sensitive handling that is out of my reach. The IP has posted on my talk. I'm hoping that people here will be able to locate a reliable source. Johnuniq (talk) 08:23, 23 February 2020 (UTC)

This is very sad. Hopefully there will be a statement from the department or university. Obviously it should not be added to the article based on the talkpage comment. (I should add that I have spent some time looking for a RS but have not found one yet.) --JBL (talk) 21:51, 23 February 2020 (UTC)

I also looked for a little while but did not find anything, so I wrote to some colleagues who I think are closer to Tsirelson in the citation graph. Maybe at least I'll hear if an official announcement is in the works. XOR'easter (talk) 22:43, 23 February 2020 (UTC)

Thanks but the IP has found a ref and added it to the article. Please have a look and see what else should be done. Johnuniq (talk) 08:49, 25 February 2020 (UTC)

I was hoping it was a hoax, though I didn't think it was very likely. --Trovatore (talk) 20:17, 25 February 2020 (UTC)

Yau's nationality

Stomatapoll has made a bunch of edits to many different articles concerning the nationality of Shing-Tung Yau. Of the two I looked at slightly closely, one did not involve any sources, while the other involved a source in Chinese; I tend to think the latter is not actually about Yau. I think this would benefit from more eyes and some discussion. --JBL (talk) 19:54, 26 February 2020 (UTC)

I didn’t look at the user’s edits, but the timeline of his nationality is fairly clear with the passages from his recent autobiography:

Stephen Hawking invited me to discuss [the proof] with him at Cambridge University in late August 1978. I gladly accepted.... Travel was difficult, however, because the British Consulate had recently taken my Hong Kong resident card, maintaining that I could not keep it now that I had a U.S. green card. In the process, I had become stateless. I was no longer a citizen of any country.... until I became a U.S. citizen in 1990.

— Yau, Shing-Tung; Nadis, Steve (2019). The Shape of a Life: One Mathematician's Search for the Universe's Hidden Geometry. Yale University Press. p. 125.

The only confusing thing is that he says in the quote that he became stateless despite not renouncing his Chinese citizenship. In fact, the New Yorker attributes the following quote to him:

I am proud to say that when I was awarded the Fields Medal in mathematics, I held no passport of any country and should certainly be considered Chinese.

— New Yorker article

.

As the footnote in Shing-Tung Yau added by another editor correctly states, he lost his HK residency card and didn't have a passport (probably what he meant by stateless in the autobiography quote) but was still legally a Chinese citizen and considered himself as such with regards to Fields Medal attribution. — MarkH₂₁^talk 20:36, 26 February 2020 (UTC)

@MarkH21: Thank you for looking into it! --JBL (talk) 13:29, 27 February 2020 (UTC)

Mar 2020

blockquote?

The Basel problem was solved by a proof that

$\sum _{n=1}^{\infty }{\frac {1}{n^{2}}}={\frac {\pi ^{2}}{6}}.$

The Basel problem was solved by a proof that

$\sum _{n=1}^{\infty }{\frac {1}{n^{2}}}={\frac {\pi ^{2}}{6}}.$

The first statement above has the displayed TeX code indented by a colon at the beginning of the line. That has long been standard usage here. The second uses "blockquote". I've run into several like that today. Is that now considered a standard usage in Wikipedia articles? Michael Hardy (talk) 01:09, 1 March 2020 (UTC)

For non-math typesetting, <blockquote> and {{quote}} are both standard. I've noticed <blockquote> used a few times for math typesetting here too though. — MarkH₂₁^talk 01:14, 1 March 2020 (UTC)

I don't think it is or should become standard, though. —David Eppstein (talk) 01:57, 1 March 2020 (UTC)

There are issues with every solution unfortunately. I don't know the specific circumstances, but using <blockquote>...</blockquote> will avoid the problem of a lack of indentation in material next to a body floating left, like at the picture I inserted above. It's possible that at least some of the cases of this being used in the wild are to try to work around this. Not even <math display="block"> will avoid that. –Deacon Vorbis (carbon • videos) 02:19, 1 March 2020 (UTC)

I've taken the liberty of modifying the above visual to show this problem. I hope no one minds. --Bill Cherowitzo (talk) 22:04, 1 March 2020 (UTC)

I would think the smaller font size of the block quote (carried through into mathematics formulas displayed that way) would be a bigger problem than the faulty indentation of the other styles. —David Eppstein (talk) 02:26, 1 March 2020 (UTC)

Interesting; Chrome reports both as exactly 49.57px tall for me. Likewise, text in blockquotes is displayed at the same size as surrounding text. I'd be curious what's causing the discrepancy. There are certainly a lot of potential places for styling rules to get tweaked. –Deacon Vorbis (carbon • videos) 04:11, 1 March 2020 (UTC)

No idea, but for me on OS X, Chrome, and the MonoBook skin, the block quotes are a little smaller in font size (both text and math) and more noticeably smaller in line spacing. —David Eppstein (talk) 06:34, 1 March 2020 (UTC)

• I'm on Firefox and the font size of the first example is distinctly larger than in the second. My personal preference would actually be to have the font slightly bigger as in the first, but indented as the second. Reyk _YO! 06:42, 1 March 2020 (UTC)
• These are not blockquotes and should not be marked up as such. Fix them as you will where you identify them. --Izno (talk) 21:45, 1 March 2020 (UTC)

User of template:Infobox polychoron.

I was very surprised that Template:Infobox polychoron was only used on the 6 regular polytopes. I'd like to see it used on ther other entries in Category:Polychora, but that may involve adding some parameters, including I think Hypervolume. I'm sure that Hypervolume can be pulled from Coxeter for the regular polytopes. I'd love any suggestions.Naraht (talk) 04:03, 2 March 2020 (UTC)

Forgive my ignorance about this particular template and going slightly off-topic from the original question, but how is this template specialized for 4-polytopes as opposed to polytopes in general? I.e. why isn’t it just Template:Infobox polytope? Likewise, why isn’t the category called Category:4-polytopes according to the WP:COMMONNAME of the corresponding article (which I understand was decided to be n-polytope in general in some older discussions at Talk:Polytope)? — MarkH₂₁^talk 05:00, 2 March 2020 (UTC)

Because it has as parameters Cell List and Face List. a 5-polytope like the 5-cube would need an entry for 4-faces as well. As for commonname, I'd actually prefer that the 4-polytope article be called polychoron, I'm not sure where to get the "Common Name" for this. Coxeter?Naraht (talk) 05:09, 2 March 2020 (UTC)

See Talk:4-polytope#It is entirely inappropriate for this article to be named "Polychoron" (2009), Talk:4-polytope#Pushing nonstandard terminology (2014), and Talk:4-polytope#Polychora again (2015). The move from the neologism "polychoron" to the much more widely used (in professional mathematics) "4-polytope" appears to have happened after the middle discussion. It's not so critical that we move the template in the same way (because its neologism isn't visible to readers) but we should do it anyway. We should certainly not push the neologisms back into view in our articles, for all the reasons discussed in the earlier discussions. (Also, anyone who has spent any effort on the polytope articles knows that they are a mass of original research, reduplicated off-topic material, and decorative but uninformative and off-topic image galleries that needs a power hose to clean out.) —David Eppstein (talk) 06:28, 2 March 2020 (UTC)

Ah, thanks! I'll go ahead and make these template/category moves then. It seems that Polychoron was moved in 2014 based on those discussions to 4-polytope but nobody noticed to do the same to the category. There seems to be strong consensus towards the "n-polytope" nomenclature, which also matches what I usually see in mathematical literature. — MarkH₂₁^talk 08:48, 2 March 2020 (UTC)

Embedded points

Hi all, are there any pages on Wikipedia for embedded points, in the sense of scheme theory: https://stacks.math.columbia.edu/tag/05AJ? Wundzer (talk) 05:08, 3 March 2020 (UTC)

Not that I’m aware of; its a reasonable article to create or perhaps a section of generic point (which somewhat covers specializations of points, but not really). Both Embedded point and Specialization of a point should probably be created at some point. — MarkH₂₁^talk 06:03, 3 March 2020 (UTC)

Embedded prime is is a redirect to Associated prime. "Embedded prime" is also defined in Primary decomposition. As primary decompositions behave well under localization, the generalization to schemes is straightforward. So, I suggest adding a section about this generalization in Primary decomposition (where this generalization is implicitely mentioned). By the way, as associated primes and embedded primes can hardly be defined independently of a primary decomposition, I would suggest to merge Associated prime into Primary decomposition. D.Lazard (talk) 10:23, 3 March 2020 (UTC)

I have changed the target of Embedded point to an anchor in Primary decomposition, where "embedded prime" is defined. D.Lazard (talk) 10:41, 3 March 2020 (UTC)

I don’t think merging associated prime to primary decomposition works, since the former article also covers the non-commutative case (for the Noetherian commutative case, as Lazard pointed out, the two topics are the same). One possibility is to split associated prime into two parts; one part is about a primary module or a prime module in the context of general module theory and then merge the other part (associated primes in the commutative ring theory) to primary decomposition. There is also a matter of decomposition of an injective module over a Noetherian ring, which is a sort of non-commutative primary decomposition, but that’s another matter. Taku (talk) 11:56, 3 March 2020 (UTC)

Draft:Convexity (algebraic geometry)

Hi, my submission for the article https://en.wikipedia.org/wiki/Draft:Convexity_(algebraic_geometry) was declined due to not having sufficient context. Unfortunately, I'm having trouble figuring out how to improve the article so there is enough context available. How can I improve it? I've looked at a couple articles, like Flat module and Algebraic stack for help, but these both have similar introductions. Wundzer (talk) 04:16, 28 February 2020 (UTC)

Did you read MOS:MATH#Article introduction and WP:TECHNICAL? As it is, your introduction is much too technical. I know that the subject is of a highly technical nature, and it seems impossible to explain the interest of the concept to a reader who knows nothing of modern algebraic geometry. But the lead must be roughly understandable to a reader who, for example, has had a graduate course of algebraic geometry. More specifically, it would be useful to explain the relationship between this meaning of "convex" and its meaning in other branches of mathematics (I don't believe that this term has been chosen at random). Also, for a non-specialist like me, it seems that the concept is related with the property of compact analytic manifolds to not have non-constant holomorphic functions that are defined everywhere. Clarifying this in the lead would help to explain the interest of the concept. I believe that it is the lack of informal explanations that has motivated the reject of the draft. D.Lazard (talk) 09:17, 28 February 2020 (UTC)

I don't think the draft is too bad -- indeed many other articles have a similarly technical introduction (and rightfully so, IMO). The overarching problem we have here is that new math articles get reviewed by (in many cases) non-math reviewers who have little to contribute other than formal nitpickings. At least that is my personal experience from the last few articles I have created.

@Wundzer: After incorporating some of D.Lazard's comments, I personally would largely ignore the "too technical" complaint. It would help, I think, if you were to add a few more references, ideally within the text (as is currently the case in two spots). Also, there is a bunch of spots where some punctuation etc. is suboptimal, this could be improved before putting it on main space. If you want, I could weigh in at the discussion whether it is too technical: I don't really think so. Jakob.scholbach (talk) 09:31, 28 February 2020 (UTC)

For being clear, I did not intended to say that the body of the article is too technical. Only that the lead is too technical, and lacks of information that is not purely technical. D.Lazard (talk) 10:13, 28 February 2020 (UTC)

I somewhat agree with D. Lazard here. Some additional context and wikilinks in the lead would help. — MarkH₂₁^talk 10:18, 28 February 2020 (UTC)

The problem here is likely just about the lead itself not giving a good informal explanation of what convexity is in this context and why it is important. I don't understand the material well, but some prose along the lines of

That the first cohomology class of the tangent bundle is zero implies that the variety has a globally generated section. For a variety to support such a globally connected section, the base variety needs to be a single connected region with no holes, i.e., it has properties analogous to the usual convex property in Euclidean geometry. Examples of convex varieties include X, Y and Z. Convex varieties are important in fields like quantum cohomology because they are particularly simple and allow for easier computation of their topological and geometric properties.

would help give context and indicated importance. --{{u|Mark viking}} {Talk} 18:51, 28 February 2020 (UTC)

I'm glad to see so many useful tips! I've updated the introduction and added many more references throughout the article. Hopefully this looks good enough. Wundzer (talk) 20:17, 28 February 2020 (UTC)

Your recent modifications are definitely improvements — thank you! I think "write one level down" is good advice for technical topics like these: the lead, at least, should say something that is helpful to readers who have less background knowledge than the primary audience. If the topic is normally taught in graduate school, then the lead should be comprehensible for advanced undergraduates. Another useful question might be, "How would I provide a preview of this material in a course that is the prerequisite for the one where it is actually taught?" I think Mark viking's suggestion for the kind of prose to include is on the right track. What property of convexity in Euclidean space is being abstracted or generalized here? In other words, why is "convexity" the term that the algebraic geometers chose, rather than anything else? That's the type of question that the lead should be helping to answer.

I'm a little leery of relying upon MathOverflow as a source. Sure, it's a good forum, and the answers that bubble to the top are usually OK, but when we point to a post there, it's not clear whether we're saying to read the answer with the green checkmark (supposing there is one), all of the answers with positive scores, or what, exactly. I think it's more useful to point directly to the papers and textbooks that get cited in the MathOverflow threads. XOR'easter (talk) 17:46, 29 February 2020 (UTC)

Hi XOR'easter, I added intuition for how convexity in the sense of algebraic geometry generalizes convexity in euclidean geometry. TBH I didn't even think of this point before, so this was a helpful question! Thanks! Also, I usually add links to mathoverflow so people can at least find a starting spot for figuring out why something is true. But, occasionally, including the posts of famous mathematicians is helpful. Should I just link directly to their response? Wundzer (talk) 19:21, 29 February 2020 (UTC)

Notice: since the discussion seems subsided and since I'm not seeing opinions that we need to keep this particular draft outside the mainspace (not in generic terms), I have moved the draft page to mainspace; further work on the lead, as needed, can continue in mainspace. -- Taku (talk) 13:27, 4 March 2020 (UTC)

Proposed merge from Ramification theory of valuations to Ramification group

I proposed a merge here from Ramification theory of valuations to Ramification group. I imagine they're fairly low-traffic pages, so any thoughts would be appreciated! — MarkH₂₁^talk 01:16, 6 March 2020 (UTC)

Proposed deletion of Structure (category theory)

I am proposing deletion of the article Structure (category theory), due to the fact that it seems unfocused/incoherent and has no essential content. Please chime in here. --Jordan Mitchell Barrett (talk) 21:21, 26 February 2020 (UTC)

This is an AfD, not a PROD, but thanks for flagging it here. Andy Dingley (talk) 21:40, 26 February 2020 (UTC)

Sounds like abstract nonsense. ;¬) JRSpriggs (talk) 02:12, 27 February 2020 (UTC)

Better abstract nonsense than Fashionable Nonsense. –Deacon Vorbis (carbon • videos) 02:22, 27 February 2020 (UTC)

Bump! The AfD was relisted and more discussion is needed, since we can’t decide on a merge/redirect target (or outright deletion)! — MarkH₂₁^talk 10:03, 6 March 2020 (UTC)

Script to detect unreliable sources

Main page: User:Headbomb/unreliable

I have (with the help of others) made a small user script to detect and highlight various links to unreliable sources and predatory journals. The idea is that it takes something like

• John Smith "Article of things" Deprecated.com. Accessed 2020-02-14. (John Smith "[https://www.deprecated.com/article Article of things]" ''Deprecated.com''. Accessed 2020-02-14.)

and turns it into something like

• John Smith "Article of things" Deprecated.com. Accessed 2020-02-14.

It will work on a variety of links, including those from {{cite web}}, {{cite journal}} and {{doi}}.

I'm still expanding coverage and tweaking logic, but what's there already works very well (e.g. picking up links to Stack Exchange in List of unsolved problems in fair division). Details and instructions are available at User:Headbomb/unreliable. Questions, comments and requests can be made at User talk:Headbomb/unreliable. Headbomb {t · c · p · b} 22:17, 9 March 2020 (UTC)

Brazilian number

I've just accepted Brazilian number at AfC. This is not a topic I grock at all, so could someone please have a look and see if the content is sensible? – Uanfala (talk) 14:46, 1 March 2020 (UTC)

Thanks for taking on this sort of technical article at AfC. The content looks sensible to me and it looks better documented than many articles of this type. As to whether the topic is notable--it is possible, but I have not checked. --{{u|Mark viking}} {Talk} 19:38, 1 March 2020 (UTC)

Isn't this exactly the same thing as described in the existing article repdigit? —David Eppstein (talk) 20:12, 1 March 2020 (UTC)

I don’t know this type of stuff, but as David Eppstein said, the two articles look about the (essentially) same topic. —- Taku (talk) 20:29, 1 March 2020 (UTC)

It does look like the same thing. I suggest merging them. Reyk _YO! 20:28, 1 March 2020 (UTC)

I'd support a merge. XOR'easter (talk) 22:05, 1 March 2020 (UTC)

Ditto. Afterwards I feel like this should be deleted (the name being something just made-up). --JBL (talk) 22:16, 1 March 2020 (UTC)

Good catch, David! They look the same to me and a merge is the way to go. A redirect is fine; it would need to be there for attribution after a merge and the name Brazilian number occurs in the wild.[2][3] --{{u|Mark viking}} {Talk} 00:26, 2 March 2020 (UTC)

Merged! It could maybe use some list-to-prose conversion, but I think it looks OK for a start. XOR'easter (talk) 02:03, 2 March 2020 (UTC)

I've received a talk page message objecting to the merge of Brazilian number to Repdigit. I'm copying over the relevant parts:

4) I really think that this article merits to have its own article. Why?

• 4.1) This article “Brazilian number” comes from the French Wikipédia article "Nombre brésilien": link below:

https://fr.wikipedia.org/wiki/Nombre_br%C3%A9silien

• 4.2) This submission "Brazilian number" is like other mathematical articles that concern number theory such as palindromic numbers, prime numbers, self numbers, Fermat numbers, Mersenne numbers, repunits, transcendental numbers, ... there is an introduction, followed by an history presentation, then different paragraphs that detailed the properties of these numbers. The structure of this article is perfect for beeing independent.
• 4.3) The Brazilian number section I have written is here 12 times greater than the original article about repdigits, this is not balanced; when there is a complement on an article, the complement is always smaller than the original text. Here, it is clearly the opposite and this cannot be good for understanding the whole article.
• 4.4) There are in the “Brazilian number” text 28 Wikipedia references (in blue) towards mathematical terms or famous mathematicians, and ten references or external links towards historical articles. I don't forget the 18 links to OEIS sequences related with Brazilian numbers. That proves that this article can (must) be autonomous.
• 4.5) About mathematical angle, all Brazilian numbers are repdigits but the converse is false. I remark also that you use my definition of Brazilian numbers to explain repdigits (thanks).
• 4.6) To finish, repdigits belong rather to recreative mathematics and Brazilian belong rather to number theory.

Hence, please, only one question, why don't you create a Brazilian number article independent as in French Wikipédia? There is no sens to put this structured article of 102 lines at the end of the repdigit article of only 7 lines...

Merci for your answer.

Best regards.

OSS117 (talk) 18:30, 2 March 2020 (UTC)

Inviting Mark viking, David Eppstein, Taku, Reyk, XOR'easter, and JBL to comment. – Uanfala (talk) 23:00, 2 March 2020 (UTC)

So it appears to me that OSS117 is incorrect on point 4.5; unless I'm missing something, Brazilian numbers are exactly the same as repdigits. (They're not the same as repunits, which might be the source of the confusion?)

If I'm right about that, then surely there should be only one article, and the question is which title should be used. I agree with point 4.6 that "repdigits" looks like an article about recreational math. If these numbers are thought to have a wider number-theoretic importance than that, then that would be an argument for putting the article at Brazilian number. --Trovatore (talk) 23:15, 2 March 2020 (UTC)

Point 4.1 is irrelevant; Wikipedias in different languages have different inclusion standards. Point 4.3 doesn't seem like a problem (the only difficulty in the reading is not a lack of balance, but the choppiness of using lists instead of prose). I don't understand point 4.4 at all. Point 4.5 is an argument that Brazilian numbers belong in an article on repdigits, being a special case of them. 7 lines on repdigits plus 102 lines on Brazilian numbers is 109 lines on repdigits. As for point 4.6, neither term seems more recreational than the other to me. XOR'easter (talk) 23:57, 2 March 2020 (UTC)

(edit conflict)On 4.5, I thought that their point is that one would implicitly fix a base a priori. But then the repdigits in a fixed base would be a proper subset of the Brazilian numbers, which is the opposite of the claim in 4.5. So I’m also unsure by what is meant by 4.5.

On 4.6, I don’t see evidence that Brazilian numbers are more researched in mainstream number theory.

Surely the existence of bluelinks in the article and a French Wikipedia article are irrelevant. — MarkH₂₁^talk 00:04, 3 March 2020 (UTC)

There is a tiny technical difference: the restriction $b<n-1$ in the quoted Olympiad problem means that the digit sequence 11 (and only that digit sequence) counts as a repdigit but not as Brazilian. (This is necessary to prevent all numbers from being Brazilian.) I don't think that difference is enough to spin out two separate articles, nor to argue that one variation is recreational and the other not (as if that is somehow a pejorative). But probably we should at least clarify that difference in the article. —David Eppstein (talk) 08:16, 3 March 2020 (UTC)

• I still think the merge was the correct outcome. Reyk _YO! 08:21, 3 March 2020 (UTC)

Hello, merci to everybody, I appreciate your answers and I'll answer to all your remarks with much details this evening (in France). OSS117 (talk) 08:58, 3 March 2020 (UTC)

Bonjour to everybody. I have read with much attention all you have written after that Uanfala put my remarks, and I try to explain with mathematical arguments why merge "repdigit" and "Brazilian number" does not look like mathematically correct.

I answer point after point to all your remarks.

* Point 4.1: "is irrelevant" (twice). Often in French Wikipédia, for mathematical articles, we write (in French) "this article comes partially or totally from the article XXX of English Wikipedia" and French Wikipédia never thinks that to propose an article coming from English Wikipedia is irrelevant; on the contrary, we are happy to use it and when possible to improve this article; hence, here, it was just an information to you.

* Point 4.2: No remark you have done.

* Point 4.3: Sorry, I have problem (English is not my native language, but I have less problem with mathematical English) to well understand this sentence "(the only difficulty in the reading is not a lack of balance, but the choppiness of using lists instead of prose) " even with help of a dictionary. What I remark is that initial repdigits article has only 7 lines and Brazilian number article has 102 lines, so it is mathematically odd to merge the second with the first. If you want, I can write later more lines about repdigits.

* Point 4.4: is very clear and details the number of distinct references; that proves that the structure of the Brazilian number article is enough correct to be autonomous, as other similar Wikipedia articles in Number Theory as palindromic numbers, prime numbers, self numbers, Fermat numbers, Mersenne numbers, repunits, transcendental numbers… and this article respects also the rules of Wikipedia.

* Point 4.5: "Brazilian numbers are exactly the same as repdigits." Non, Brazilian Numbers are repdigits in some base, yes, but not all repdigits are Brazilian; the counterexamples are 1, 2, 3, 4, 5, 6, 9 and 11. Again, I read " 7 lines on repdigits plus 102 lines on Brazilian numbers is 109 lines on repdigits", these are two distinct sets with not the same position; in addition: 7 (little) + 102 (large) = 109 (little).

* Point 4.6: In Brazilian numbers theory, there exist theorems about Fermat numbers, Mersenne numbers, Sophie Germain primes, twin primes... there are connections with Goormaghtigh conjecture or equation of Nagell-Ljunggren or other Diophantine equations studied by Kustaa Inkeri,... In repdigits, there are references with numerology 666 or 777, never in Brazilian numbers. These are two distinct mathematical words.

Please, I propose other new last comments.

* I know it is "irrelevant" but in French Wikipédia there are two distinct articles for "nombres uniformes" and "nombres brésiliens".

* In French Wikipédia, I have realized a lot of work to put blue links towards the article "Nombre brésilien" for around 200 numbers, and also I have created some paragraphs about Brazilian numbers in existing articles, for example for primes, Sophie Germain primes… With the merge of Repdigits + Brazilian numbers in English Wikipedia, it will be no interesting to improve here some articles.

* Also, in Mathematics, we say 20 is Brazilian (that means that = 22 in base 9), but we never say 20 is repdigit; also, we say 43 is a Brazilian prime (because = 111 in base 6) but we don't say 43 is a prime repdigit. There exists a constant of Brazilian primes, there is not a constant of repdigit primes. These are two distinct concepts.

So, for all these miscellaneous reasons, I sincerely think that the merge is not a correct outcome, and must create confusion between these two mathematical concepts; I read what you wrote before Umfala posts my remarks; of course to create blue links between the two articles Repdigit and Brazilian Numbers would be necessary.

Thanks for reading, not forget that English is not my native language.

OSS117 (talk) 18:57, 3 March 2020 (UTC)

Good evening,

Please, nobody?

Some new comments about your merge of the proposed draft "Brazilian number" of 102 lines with the existing "Repdigit" article of 7 lines.

When a internet user looks for "repdigit" and finds English wiki article, he reads the content:

1. History (yes, but it is the history of Brazilian numbers)

2. Some first properties (of course, but these are first properties of Brazilian numbers)

3. Primes and repunits (linked to Brazilian numbers not to repdigits)

4. Non-Brazilian composite numbers (sequence = 4, 6, 9, 25, 49, 169, 289, 361, 529,... )

5. Numbers several times Brazilian (it is not "numbers several times repunits").

6. See also (towards repunits, yes it is right here)

7. References: the 1st reference is for repdigit (it is right), but the references 2, 3, 4, 5, 6, 7, 8 and 9 relate Brazilian numbers.

Thanks for your comments.

OSS117 (talk) 21:50, 4 March 2020 (UTC)

• I still think the merge was the correct outcome. —David Eppstein (talk) 21:55, 4 March 2020 (UTC)

I agree with everyone else that there should be only one article here. (Of course that does not forbid editing the merged article!) --JBL (talk) 10:32, 5 March 2020 (UTC)

Also it might be useful to see more evidence regarding which title it should appear under ("repdigit" vs "Brazilian number"). --Trovatore (talk) 18:41, 5 March 2020 (UTC)

"Brazilian number" is such an obviously terrible name .... Yes, I know, that's not relevant to how article name decisions get made here. --JBL (talk) 18:57, 5 March 2020 (UTC)

Hello,

First, the draft “Brazilian number” was not accepted by English Wikipedia because “This submission provides insufficient context for those unfamiliar with the subject matter”. !!!!!!!!

Second, I learn later that this draft “has been created”...but I understand this draft has been merged with repunit because "Isn't this exactly the same thing as described in the existing article repunit?"

I put another last explanation that shows that merge was not the correct outcome.

• The first twenty repdigits in the encyclopedia of sequences OEIS are:

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 22, 33, 44, 55, 66, 77, 88, 99, 111 … (sequence A010785 in the OEIS),

and, in the same encyclopedia,

• The first twenty Brazilian numbers in OEIS are:

7, 8, 10, 12, 13, 14, 15, 16, 18, 20, 21, 22, 24, 26, 27, 28, 30, 31, 32, 33, … (sequence A125134 in the OEIS).

So, there are only four identic terms {7, 8, 22, 33} among the first 20 terms of each sequence. In OEIS, there are more than 100 sequences relative to Brazilian Numbers.

Also, my friends and I don't understand the meaning of "(the only difficulty in the reading is not a lack of balance, but the choppiness of using lists instead of prose)." Please, thanks to explain with other words what this sentence means.

To finish, I read also that "Brazilian number" is " an obviously terrible name".

In these conditions, the best decision is to follow your suggestion "Of course that does not forbid editing the merged article!"

Thanks very much for your help.

OSS117 (talk) 10:19, 7 March 2020 (UTC)

I don't understand the issue here at all. There does seem a distinction between "repdigit" and "Brazilian number"; so the question is whether the distinction warrants a separate article. In Wikipedia, there does not need to exist a one-to-one correspondence between articles and concepts; *essentially* the same but distinct concepts can be treated in the same article; the merger does not mean there is no distinction. Whether ""Brazilian number" is a terrible name" is completely irrelevant. There are way too many terrible names ("integral domain"!) in mathematics I love to correct. -- Taku (talk) 18:58, 7 March 2020 (UTC)

Bonjour Taku, Thanks for your message. Yes, you ask the right "question" but the answer looks like rather subjective here. Some participants have decided 1st March to merge "repdigit" and "Brazilian number". Since, although I wrote a lot of mathematical reasons to explain this merge is a nonsense, the participants think the merge was the correct outcome. Merge a well documented mathematical article of 102 lines at the end of a "repdigit" article of only 7 lines (whose 2 lines for numerology) is also difficult to understand. So, the best issue for this structured mathematical article about "Brazilian number" was to delete this article from the "repunit" article. Very sorry for the time you have lost with this true mathematical article "Brazilian number". OSS117 (talk) 22:28, 9 March 2020 (UTC)

@OSS117: I'm thoroughly confused as to why you deleted the content on Brazilian numbers at Repdigit. As Taku and others point out, the naming is a separate issue from whether they should be merged. I.e. they should be one article, but it could certainly be at the article named Brazilian number rather than Repdigit, with the mention of repdigits coming secondary to that of Brazilian numbers. There's no need to remove all of the content.

Also sorry for not explaining what XOR'easter probably meant earlier by the only difficulty in the reading is not a lack of balance, but the choppiness of using lists instead of prose. Here's my interpretation. C'était essentiellement que: le fait que la majorité de l'article concernait les nombres brésiliens n'était pas une cause de difficulté de lecture, mais le fait que la majorité de l'article a été écrit sous forme de liste était une cause (en fait, la seule cause) de difficulté de lecture. Ici, choppiness signifie qu'une liste présente le matériel dans un rythme très staccato et les faits dans une liste ne coulent pas bien. Les connecteurs logiques en écriture de prose collent ensemble le choppiness (les «saccades» de mots)... — MarkH₂₁^talk 22:35, 9 March 2020 (UTC)

I have restored the content that OSS117 removed. I have also started to try a bit to make it look more like an encyclopedia article. Further help in that regard would be welcome. I continue to feel that the name Brazilian number is incredibly terrible, but it is possible that it would be a better title for the article, given that there are at least two sources that seem to use it. --JBL (talk) 23:08, 9 March 2020 (UTC)

I tried searching Google scholar, but just searching for "Brazilian number" alone found a huge number of false positives (9 out of the first 10 results appeared to be for unrelated topics). Filtering out the results that also included the phrase "base b" may be a little unfair, because work on repdigits might be more likely to not specify a base, but it's more likely to only produce relevant hits. "repdigit" "base b" had 35 hits, and "repdigits" "base b" had 40. "Brazilian number" "base b" had 2 hits, and "Brazilian numbers" "base b" had one. Similarly, MathSciNet has 49 papers that include "repdigit" anywhere, 42 with "repdigits", and none with "Brazilian number" or its plural. I think that makes it clear enough which name is the WP:COMMONNAME. —David Eppstein (talk) 23:44, 9 March 2020 (UTC)

Bonjour, I see you have improved the article repdigit and the merged part Brazilian number. It is a real good job, congratulations. I retain some of your ideas to improve the French Wiki Nombres brésiliens. Thanks to JBL for I am "very welcome to continue contributing to the article". First, I want to improve the French Wiki, and I go back here. What do you prefer? I propose here in this talk page some improvements or precisions that I think it could be interesting for the article and you say yes or no, or I put directly in repdigit article what I think improvements or precisions and then you fix or delete, in the two cases, I shall be ok with all you choose or prefer. Have a nice day. OSS117 (talk) 06:52, 12 March 2020 (UTC)

MathGenealogy deprecated ?

The following edit suggests that the template:MathGenealogy is unnecessary:

template removed from Joachin Lambek

Searching the archives no such suggestion was found. If WikiData includes the link, is it not for articles ? — Rgdboer (talk) 02:13, 9 March 2020 (UTC)

It's already included in the Authority control line (under "MGP") so it's a bit redundant as a separate external link. I would still use it as a reference for information about dissertation and students, though, for instance in this case on the sentence "Lambek supervised 17 doctoral students, and has 73 doctoral descendants as of 2019", which is currently unsourced. One other note: when the MGP id is present on Wikidata, you can use the {{mathgenealogy}} template without any parameters (it will find the id from Wikidata). —David Eppstein (talk) 06:52, 9 March 2020 (UTC)

Ok, so MGP is duplicated by Authority control. Has now been cited inline to support the quoted statement. Thank you for your in-depth response. — Rgdboer (talk) 00:43, 14 March 2020 (UTC)

I, for one, have no idea how to use the Authority control line. I suspect there may be others in this situation. So removing something because it is redundant with the Authority control line seems to me to be inappropriate. JRSpriggs (talk) 07:12, 15 March 2020 (UTC)

As a reader? It's a collection of links to certain other sites on the same person, mostly library catalogs, in a more abbreviated format than the external links section. You can click on them like you would any other link. As an editor? Add {{Authority control}} to the bottom of a biographical article (and if you like add parameters like MGP=id and wait for some gnome to move them to Wikidata where they belong). —David Eppstein (talk) 07:33, 15 March 2020 (UTC)

Converse (logic) and Converse implication

Is there a reason to have these separate articles? They have both been around for a long time. --JBL (talk) 16:40, 10 March 2020 (UTC)

My two cents: Converse implication is more symbolic and visual, such as an engineer might like. Converse (logic) is more verbose and formal in tone, such as a philosopher might like. I think both kinds of description are useful and these two articles could be usefully merged. --{{u|Mark viking}} {Talk} 17:48, 10 March 2020 (UTC)

Same topic, so they should definitely be merged. Converse implication should probably be merged into Converse (logic) since the latter is the more general title (and includes the material on the categorical converse). — MarkH₂₁^talk 01:05, 12 March 2020 (UTC)

I don't think there's much at converse implication worth merging. It could just be done as a redirect. —David Eppstein (talk) 07:35, 15 March 2020 (UTC)

I suppose so, although we could move the half sentence about notation from the lead and use the (very) colorful pictures! — MarkH₂₁^talk 08:32, 15 March 2020 (UTC)

Thanks Marks and David -- I have attempted a comprehensive merge. --JBL (talk) 13:24, 17 March 2020 (UTC)

Proposed inclusion of code snippets

The idea is to include simple code snippets, at the end of each math article, to connect concepts and algorithms. An important aspect of this type of approach is to bind concepts to something practical, encouraging through that, the experimentation of mathematical concepts.

As examples of that suggestion, check Outer product and Dot Product in Linear Algebra.— Preceding unsigned comment added by Alexzumalde (talk • contribs) 11:06, 17 March 2020 (UTC)

Please, add new threads at the bottom of talk pages, and sign your posts there with four tildes (~~~~).

This idea has been widely discussed in Wikipedia. The resulting consensus is that explicit source code is useful only if it adds something to the description of the algorithm in pseudo-code (see MOS:MATH#Algorithms, MOS:CODE, MOS:ALGO). In the article that you have edited, the algorithms are so simple that pseudo-code is not even useful, and anybody who knows any programming language should easily produce himself an implementation similar to yours. Also, your implementation of the dot product is not a good one, as explained in the preceding subsections. So, your addition is not only not useful, but also misleading, as suggesting that it could be used without care. For these reasons, I'll delete your edits. D.Lazard (talk) 12:26, 17 March 2020 (UTC)

"at the end of each math article"...? That would be funny if it weren't so ...irrational. What code snippet would you like to put at the end of article about Euclidean plane? about a homology? about convex function?
Most mathematical concepts and problems are not algorithms, so there is no place and no reason to put any code snippets in most math articles. --CiaPan (talk) 18:20, 18 March 2020 (UTC)

To add to the pile-on, I think it is highly inappropriate to add code snippets for implementations of simple mathematical formulas. And in cases where an article discusses a non-trivial algorithm, pseudocode is a better choice than code. —David Eppstein (talk) 18:47, 18 March 2020 (UTC)

Recent mathematical deletion sorting

In case anyone here isn't already aware of Wikipedia:WikiProject Deletion sorting/Mathematics, we currently have seven ongoing deletion discussions (including new ones on multiplicative calculus and of four Pakistani mathematicians) and one prodded article listed there. Please participate with your opinions. —David Eppstein (talk) 17:46, 18 March 2020 (UTC)

Really, Wikipedia:WikiProject Mathematics/Article alerts is the page people should watch. It covers Delsort and a lot more than Delsort. Updates every day too. Headbomb {t · c · p · b} 19:17, 18 March 2020 (UTC)

Also why tagging pages with {{WP Mathematics}} is important, (or rather whichever of {{maths rating}} or {{maths banner}} applies, because I'm not spending time on remembering which applies, because there is no reason to have two distinct banners and these should be merged). Headbomb {t · c · p · b} 19:23, 18 March 2020 (UTC)

Fundamental theorem of linear algebra

I have open there a discussion for deciding whether Fundamental theorem of linear algebra should be moved, merged or deleted. Suggestions are welcome. D.Lazard (talk) 15:18, 22 March 2020 (UTC)

This seems tricky. I agree that the name is not standard; probably we have it because MathWorld does. Apparently in some texts the trivial result that a linear transformation is determined by its values on a basis is honored with the name FTLA. If something is going to exist at this title, it's not really clear what mathematics it should contain, or what other articles it should point to. Maybe deletion is the best option. --JBL (talk) 20:34, 23 March 2020 (UTC)

Draft:Hyperbolastic Functions

A review of this draft is requested. Should it be accepted?

I don't really understand, but I have forgotten all of the higher math that I learned fifty years ago. Robert McClenon (talk) 03:26, 24 March 2020 (UTC)

If you don't mind Robert McClenon I'm going to add Draft:Modular_Forms_Modulo_2 as well to this request for review. Sulfurboy (talk) 21:42, 24 March 2020 (UTC)

User:Sulfurboy - Why would I object to adding to a request about something that I no longer understand? Robert McClenon (talk) 22:14, 24 March 2020 (UTC)

@Sulfurboy: Without going into the details on the page, the Draft:Modular_Forms_Modulo_2 is a reasonable and notable topic, and the draft seems correct and well-referenced at first glance. However, it should really be part of a Modular forms modulo p article, since a lot of the details mod 2 are the same in the more general mod p theory. — MarkH₂₁^talk 22:31, 24 March 2020 (UTC)

MarkH21, So to clarify, you think it should be named Modular forms modulo? Or was that a typo that created a redlink when you meant another page. Sulfurboy (talk) 23:01, 24 March 2020 (UTC)

@Sulfurboy: there should be a p, so the redlink that I wrote is the article title that I had in mind. The article should then be slightly rewritten to separate the general prime p case from the case of p = 2.

If I have time, I may get around to doing some of that writing. — MarkH₂₁^talk 23:34, 24 March 2020 (UTC)

See also Wikipedia talk:WikiProject Medicine#Draft:Hyperbolastic Functions. WhatamIdoing (talk) 15:31, 25 March 2020 (UTC)

There's yet another draft that requires review from someone with mathematical expertise, Draft:Hb-graphs. --Cerebellum (talk) 01:31, 27 March 2020 (UTC)

I'm not sure why we're putting all of these in one section, but in any case, Cerebellum, I poked around a little, and this doesn't appear sufficiently notable for an article. Just about every reference to it seems to be by the same 3 or so people, which is a good case for WP:TOOSOON. The sources that are already there echo this I think. But if anyone else can find more that I didn't, please chime in. –Deacon Vorbis (carbon • videos) 02:07, 27 March 2020 (UTC)

Normalization

platinum ratio ? 2601:281:CC80:2F50:95AC:31F3:E071:B6A3 (talk) 19:25, 26 March 2020 (UTC)

Please be more specific. To which article are you referring (please provide a link) and what is the problem? JRSpriggs (talk) 05:38, 27 March 2020 (UTC)

It smells like a joke based on the name of Golden ratio to me... --CiaPan (talk) 21:34, 27 March 2020 (UTC)

Symmetric successive over-relaxation

We need to improve formulation of Symmetric successive over-relaxation. --Kulgai (talk) 06:36, 31 March 2020 (UTC)

• That's just one of squillions of mathematics articles with no context and difficult details that are impenetrable to a non-specialist. Reyk _YO! 14:25, 31 March 2020 (UTC)
• Also the two references are not wp:Reliable sources, and I have tagged the article accordingly. D.Lazard (talk) 14:41, 31 March 2020 (UTC)
• Until it's better sourced and demonstrates a need for a separate article, it seems like a merge to Successive over-relaxation (along with {{R with possibilities}}) might be reasonable. As a side note, look at all the code there; should that simply be scrubbed? –Deacon Vorbis (carbon • videos) 14:55, 31 March 2020 (UTC)
  • On the last point, we don't need both common lisp and python examples. The python example is probably more accessible to the average reader and should be the one kept. I'd be in favor of keeping one code example, as pseudocode can be esoteric for those not used to reading it. --{{u|Mark viking}} {Talk} 18:20, 31 March 2020 (UTC)

Apr 2020

Edit war at Tangent half-angle substitution

User:Nerd271 seems to want the opening sentence of this article to call this substitution the Weierstrass substitution without mentioning that there is any doubt about the justice of that name, or that Euler, who died long before Weierstrass was born, introduced this substitution.

The only people who have less understanding of, or respect for, historical accuracy than authors of mathematics books are those who edit Wikipedia's article about George Washington to say that he chopped down a cherry tree.

Can anyone adduce any respectable evidence that Weierstrass was ever aware of this substitution? (Short answer: no.) (Long answer: I will pay a major fortune, US$5.12 (five dollars and twelve cents, a power of 2) to whoever can do that during April 2020.) Michael Hardy (talk) 18:56, 1 April 2020 (UTC)

PS: I had left the article in a state where it refers to the tangent half-angle substitution in the opening sentence and later says some books call it the Weierstrass substitution. Michael Hardy (talk) 18:58, 1 April 2020 (UTC)

@Michael Hardy: The source you used contains nothing more than a general-interest biography of Euler. I searched it for the book that was mentioned in the citation, but it was simply not there. Unlike what its name might suggest, it is not a depository of Euler's works. Claims that cannot be supported by the citations that follow should be removed. Please see WP:VERIFY. In addition, this method is commonly known as the 'Weierstrass substitution' and the page should have that name per WP:COMMONNAME. Nerd271 (talk) 19:03, 1 April 2020 (UTC)

@Michael Hardy: For convenience, let's keep the discussion on the article's talk page. Nerd271 (talk) 19:10, 1 April 2020 (UTC)

Notability of "Integer solutions of elliptic curves"?

Hi, I'd like to seek input on whether the captioned title would be considered notable, given the works of previous mathematicians. Thanks. TLOM (The Lord of Math) (Message) 07:45, 4 April 2020 (UTC)

This is not only highly notable, but also well covered in Wikipedia, see Elliptic curve#Elliptic curve over the rationals, and the subsection Elliptic curve#Integral points. D.Lazard (talk) 08:32, 4 April 2020 (UTC)

Maybe the better question is whether rational points on an elliptic curve should exist as a separate article. I’m inclined to say yes; there is even a textbook on the topic [4]. —- Taku (talk) 11:17, 4 April 2020 (UTC)

Spam article on possibly notable topic

I am bumping this back to the talk page from the archive, since an AfD has been opened and the page creator left a comment here. --JBL (talk) 13:21, 4 April 2020 (UTC)

Draft:Word-representable graph was written by an editor who is a name match for the claimed inventor of the term, whose research also dominates the references. Is this actually a valid topic, or is it vanity spam? Guy (help!) 09:38, 5 February 2020 (UTC)

I don't recognize it. But that doesn't mean it doesn't exist. — Arthur Rubin (talk) 09:47, 5 February 2020 (UTC)

This is a real topic and Kitaev is a real mathematician. It is fairly new (introduced in the last 15 or so years) and Kitaev has been heavily involved in studying and promoting it (along with a varied group of coauthors), but glancing through MathSciNet I see a dozen or more papers about this topic in non-spam journals by sets of authors that do not include Kitaev. --JBL (talk) 12:44, 5 February 2020 (UTC)

(Probably I should give a COI notice that Kitaev wrote a letter of recommendation for me 10 years ago when I applied to post-docs, though we haven't had significant contact since.) --JBL (talk) 12:45, 5 February 2020 (UTC)

Are you thinking of Alexei Kitaev? That's a different Kitaev than S. Kitaev, from what I can tell. 67.198.37.16 (talk) 01:09, 25 February 2020 (UTC)

What a deeply bizarre question; I don't even know how to begin to respond. --JBL (talk) 01:39, 25 February 2020 (UTC)

I really don’t think it’s a spam. It is actually quite nice that the article is written by the originator of the subject, since that person must know the best. Of course, we have to watch out for a self-promotion but as far as I can tell that’s not an issue here. (It’s only an issue if the topic is fringe; i.e., not something studied in the mainstream mathematics community.) —- Taku (talk) 20:26, 5 February 2020 (UTC)

Not spam, but very new topic (mostly developed in the last five years) with limited literature as a result. It's not WP:FRINGE, but probably not mature or well-cited enough to be considered WP-notable as an article subject yet. — MarkH₂₁^talk 20:48, 5 February 2020 (UTC)

(Cf. User talk:S. Kitaev#Word-representable graph moved to draftspace.) Given my mathematical background, I really cannot tell whether the topic is too new for Wikipedia (e.g., in computing, 5-10 years might be long enough for encyclopedic treatment). Maybe some other editors in the project can weight in? —- Taku (talk) 19:39, 11 February 2020 (UTC)

I am somewhat surprised at it being labeled "too new" -- I mean, it is fairly new, but there seems to be an established literature around it, and Kitaev has written a book on the topic. The COI aspect is of the kind that doesn't bother me, personally, much (though YMMV) -- we have a legitimate researcher writing about their legitimate research. I personally would have just cleaned out the most over-the-top bits (e.g., the bibliography of papers, which is certainly not maintainable long-term) and let it live in mainspace. --JBL (talk) 00:02, 12 February 2020 (UTC)

There’s little literature on the subject independent from Kitaev though. — MarkH₂₁^talk 04:21, 12 February 2020 (UTC)

Like I said, I went through MathSciNet and (filtering out false positives) there are a dozen papers on the topic that do not have him as an author. For my taste, that's well over the "is this a real thing?" line (though again YMMV). --JBL (talk) 14:28, 12 February 2020 (UTC)

I suggest moving the article from draft space to main article immediately. I've never heard of this, but its clearly a good-quality article on something that is rather remarkable and quite interesting. I'm wondering how it might relate string rewriting to graph rewriting. What about directed graphs? So, semi-commutative monoids, e.g. history monoids have word representations and arise with things like parallel communicating finite state machines (which are just directed graphs). There's a bunch of interesting questions that could be posed. (All of mine are trivial.) Sorry I'm easily excitable. 67.198.37.16 (talk) 01:15, 25 February 2020 (UTC)

I'm easily excitable. Indeed. --JBL (talk) 01:39, 25 February 2020 (UTC)

For now, I have put the article back at the mainspace (since the initial concern has been proven invalid). It does appear to have a COI concern; so I have put the COI template. —- Taku (talk) 23:14, 27 February 2020 (UTC)

Hi everyone and thanks for your opinions about the page created by me. I was not aware of this discussion but Guy let me know about it yesterday, and he said that I can contribute to it. I was thinking to comment on some of your points which would hopefully clarify the situation. Yes, I’m a real mathematician http://personal.strath.ac.uk/sergey.kitaev/index.html not related in any way to Alexei Kitaev and I indeed wrote a letter of recommendation for JBL in Sept 2011 :) This is my very first contribution to Wiki, and I should admit that I probably violated (unintentionally!) some of the basic principles of Wiki for which I’m sorry. When I was creating the page, I was thinking to produce a high quality, useful page similar to the page about another area of my research interest, namely, https://en.wikipedia.org/wiki/Permutation_pattern , and I thought I’ve succeeded (at least it was appreciated by the many people working in the area), but then problems came along with various issues around Wiki policies. I still don’t see anything wrong with me creating the page, rather than someone else doing this as indeed probably no one knows this subject better than me, and every statement in the article is supported by an explicit reference to a published source, so every one could check that this is not a spam article, e.g. by following the references, or by contacting any of the 35+ researches mentioned on the page (in the references). This is true that I’m involved in the majority of publications in the area so far, but there are many other papers related to the topic that I have no involvement in, and the area is definitely mature enough (with a Springer book published about it, so cannot be WP:TOOSOON) to have a Wiki page dedicated to it (although, of course, I’m biased when saying this). I think it’s indeed a good idea suggested by someone to make the article a bit less technical, or at least to have some intro that can be understood by non-experts. Finally, 67.198.37.16 suggested several interesting ideas for further development of the area which I have no idea about except the case of directed graphs is handled by the notion of semi-transitive orientation. Namely, if your graph is oriented in a semi-transitive way, you can represent it by words, if not then you cannot do it. Thanks again for all your opinions. --S. Kitaev (talk) —Preceding undated comment added 06:24, 3 April 2020‎

The AfD is here. --JBL (talk) 13:22, 4 April 2020 (UTC)

Roland Richardson

I have just put up an article on this mathematician, chiefly notable for his administrative contributions as a dean at Brown and as secretary of the American Mathematical Society. Someone who is a mathematician could probably put more into it about his mathematical contributions. His PhD was on "Improper Multiple Integrals"; he was a student of James Pierpont at Yale. Brianyoumans (talk) 15:59, 4 April 2020 (UTC)

Draft on Copula

Hi all, I have recently been directed here. I have been trying to write a short article on Copula, and it keeps getting rejected for one or the other reason (https://en.wikipedia.org/wiki/Draft:Copula_in_signal_processing). I would be thankful if someone from WikiProject Mathematics could help. Thanks Robert McClenon for introducing me to this place. Earthianyogi (talk) 17:06, 7 April 2020 (UTC)

Hi Earthianyogi, and welcome to the Wikiproject. The draft you wrote looks pretty good, except for the lead/introduction. For technical articles we try to give some context and an informal description of the topic up front. Our guideline for accessibility of technical articles is WP:TECHNICAL; take a look. But before investing in more effort on this, take a look at Copula (probability theory); it is a well-developed article that seems to cover the same topic; that is, what about your draft is specific to signal processing?. If so, you might see if there is any material in your draft worthy of merging into that article. --{{u|Mark viking}} {Talk} 17:35, 7 April 2020 (UTC)

User:Mark viking Thank you for your suggestions. Yes, you are absolutely right that this article is about copula in signal processing. I have read this article Copula (probability theory), and created 2 sections in it as well. One about the use of copula in medicine and other in signal processing. I also made some other edits to this page. I already proposed to merge the two articles, but it seems like many different people with many different opinions have a say on why gets listed on Wikipedia. I was hoping to put a page with the current content on it, and use the help of more experienced editors to improve it. But it seems that I am not getting anywhere... Also, I do not believe that a person with less mathematical understanding would be interested in this article anyways; however, it may not always be the case.

Disambig group algebra

Hi all. I have just turned group algebra into a disambig page as we have two articles group ring and group algebra of a locally compact group (the former a concept in ring theory, the latter in functional analysis). This, quite predictably, resulted in a number of internal links to this new disambig page that need to be disambig'ed. I have done a few but I can also use helps from other editors with free time (or those pretending to have free time). —- Taku (talk) 14:34, 7 April 2020 (UTC)

Somehow related: I have split off a section in group algebra of a topological group to stereotype group algebra. I am not sure if this concept is notable (in the sense of Wikipedia) or not. *If* notable, it needs some non-primary references. —- Taku (talk) 15:41, 7 April 2020 (UTC)

A similar issue with stereotype space. If no one can find a non-primary ref, I’m planning to nominate those articles for deletion. —- Taku (talk) 19:54, 7 April 2020 (UTC)

There is now a dispute on the notability of stereotype space at Talk:Stereotype space#Notability between me and the inventor of the concept. I cannot say I am very familiar with this area so inputs from other editors can be useful and welcome. —- Taku (talk) 00:42, 8 April 2020 (UTC)

Given the above concern, I have nominated stereotype space for deletion at Wikipedia:Articles for deletion/Stereotype space. I don't see a choice here. -- Taku (talk) 12:14, 8 April 2020 (UTC)

If possible, please participate in the discussion; opinions from other editors can be helpful here. —- Taku (talk) 14:33, 8 April 2020 (UTC)

There is also a dispute at Talk:Group algebra of a locally compact group. —- Taku (talk) 14:39, 8 April 2020 (UTC)

Gentlemen (and ladies), are there mathematicians here? What I see in this discussion needs understanding and explanation by specialists. Eozhik (talk) 15:32, 8 April 2020 (UTC)

Discrete analytic function?

This makes me wonder whether we ought to have an article titled Discrete analytic function. Michael Hardy (talk) 18:56, 7 April 2020 (UTC)

The question is whether it is a sufficiently independent topic from circle packing theorem, the main article in this area. —David Eppstein (talk) 19:00, 7 April 2020 (UTC)

For now I've redirected it. Michael Hardy (talk) 15:08, 9 April 2020 (UTC)

Biquadratic function

There is a discussion at Wikipedia:Redirects for discussion/Log/2020 April 9#Biquadratic function about the primary meaning of the term. D.Lazard (talk) 20:06, 9 April 2020 (UTC)

Containment order

Many times I have heard of a set of sets being partially ordered by inclusion, but I don't know that I've ever heard of its being partially ordered by "containment". Should the article titled Containment order be re-titled Inclusion order or something like that? Michael Hardy (talk) 01:47, 10 April 2020 (UTC)

In my experience, the usual term is "reverse inclusion". --Trovatore (talk) 01:48, 10 April 2020 (UTC)

Maybe that's because you work in mathematical logic. Could we hear from a topologist? Michael Hardy (talk) 02:41, 10 April 2020 (UTC)

I'm not a topologist nor a logician, but both "inclusion order" and "reverse inclusion order" are natural to me while "containment order" is not. Reverse inclusion order and inclusion order are just converse to each other. I don't have any sources for you though, and some should be added before a move is made. — MarkH₂₁^talk 05:09, 10 April 2020 (UTC)

I'm also not a topologist nor a logician. Nor really an order theorist despite one paper in Order. Anyway, both inclusion and containment (in the formulations "partially ordered by X" and "X order") appear in the literature, but Google scholar hit counts suggest that inclusion is far more frequent. Examining the results shows that "containment" is also more likely to be used for other objects (e.g. geometric shapes) rather than abstract sets. —David Eppstein (talk) 05:44, 10 April 2020 (UTC)

Containment order has a particular meaning in geometry, where it means an ordering that can be mapped, preserving a proper inclusion ordering, onto similar shapes in a Euclidean space. Here is a review paper on containment order. I've seen the term used in spatial and GIS contexts, too. With a survey article, this containment is likely notable independent of inclusion. --{{u|Mark viking}} {Talk} 17:22, 10 April 2020 (UTC)

Short descriptions and See-also sections

I suggest to complete MOS:MATH by a section on short descriptions and See also sections. I could be placed as the last subsection of MOS:MATH#structure. Here is a suggestion for this section.

According to WP:Short description, every article should have a short description. This allows the reader to know what about is an article without having to open its page.

Sort descriptions are visible at the top of a page on mobile devices, and also on desktop browsers after activation of the relevant gadget (see WP:Short description#Instructions).

Short descriptions are particularly useful in sections "See also" as they allow to transform automatically an indiscriminate list of links into a more useful annotated list. For example, some see-also sections contain the link

• Lill's method

If the link is entered as {{annotated link|Lill's method}}, it becomes

• Lill's method – Graphical method for the real roots of a polynomial

Short descriptions must appear in a template {{short description}} for being visible in annoted links. Short descriptions are also useful for redirects to a section or an anchor. In this case the {{short description}} must appear in the line that follows the magic word "#Redirect".

Please, give your opinion on such an addition in MOS:MATH, and be free to improve my draft.

Adapting the see-also sections this way requires some work, but it is useful not only for readers, but also for project members: the spam items become immediately visible. D.Lazard (talk) 14:06, 13 April 2020 (UTC)

This doesn’t seem math-specific at all, should this be in MOS:MATH or elsewhere? Also what about is an article and they allow to transform automatically are somewhat awkward. Using what an article is about and they transform are better. — MarkH₂₁^talk 14:18, 13 April 2020 (UTC)

The specificity of mathematics, is the high numbers of articles whose title is meaningful only for people who know already the content. For example all articles named "Someone's theorem", "Someone's idendity", and so on (how many members of this project knew Lill's method before my post?). While editing some see-also sections, I was astonished by the number of item that should not be there, and for which this appeared clearly only after having added a short description and an annotated link. D.Lazard (talk) 14:47, 13 April 2020 (UTC)

Discussion on primary podcast source vs. Notices of the AMS and Math Genealogy for doctoral advisors

A user has removed the advisor of Eric Weinstein cited to both the Notices of the AMS and the Math Genealogy Project on the basis that the subject himself stated in a podcast that he had no advisor. I have opened a discussion here, and participation on which source to use is welcome. — MarkH₂₁^talk 13:25, 14 April 2020 (UTC)

Confusing statement

Please see Talk:Ammann–Beenker tiling#Strange statement. Feedback is welcome. Toshio Yamaguchi (talk) 18:28, 14 April 2020 (UTC)

Statistics question at Talk:2019–20 coronavirus pandemic#Epidemic curve graphics

 Some attention from statistics-inclined Wikipedians would be helpful for resolving the question at Talk:2019–20 coronavirus pandemic#Epidemic curve graphics. Thanks! {{u|Sdkb}} ^talk 22:49, 15 April 2020 (UTC)

The curves labelled 1 and 2 might be correct. The other curves (3, 4, 5, and 6) are certainly wrong. They all refer to the number of cases. What they all leave out is the number of deaths which is the significant difference between mitigation by social distancing and the lack thereof. JRSpriggs (talk) 10:42, 16 April 2020 (UTC)

@JRSpriggs: To keep discussion centralized, could you please copy your comment over to the pandemic article? It's not going to be seen here. {{u|Sdkb}} ^talk 08:11, 17 April 2020 (UTC)

Notability of Carol number and Kynea number

Back in 2009, the former was AFD-ed at Wikipedia:Articles_for_deletion/Carol_number with a no-consensus result. A decade on, it doesn't look like these numbers are any more notable, and the sourcing remains questionable. Should they be (re)nominated? Boldly merged ref the AFD? ^~Hydronium^~Hydroxide^~(Talk)~ 15:09, 17 April 2020 (UTC)

I am surprised that that discussion was closed as no consensus -- to me, it looks like there was a weak consensus to delete. It might be worth another swing at AfD. (Merging the two would also be an improvement.) --JBL (talk) 15:36, 17 April 2020 (UTC)

Both of them could be selectively merged to near-square prime, which could also incorporate some material from Landau's problems. XOR'easter (talk) 14:00, 18 April 2020 (UTC)

Self-promotional additions to Riemann zeta function

These additions to Riemann zeta function appear self-promotional (compare the names of the reference author and the Wikipedia editor). Are they appropriate for the article or WP:UNDUE? —David Eppstein (talk) 18:45, 18 April 2020 (UTC)

Surely the standards for what is due weight regarding the Riemann zeta function are pretty high. I'm doubtful that work which is new and virtually uncited could qualify, even though it appears to be reliably published. XOR'easter (talk) 18:50, 18 April 2020 (UTC)

It seems undue, and the preceding reference (2017 unpublished Researchgate reference) is an even worse offender. I’ve removed them for now. — MarkH₂₁^talk 19:04, 18 April 2020 (UTC)

Thanks. XOR'easter (talk) 19:44, 18 April 2020 (UTC)

Yes, thanks! I agree with this removal also. —David Eppstein (talk) 20:07, 18 April 2020 (UTC)

Navbox: Functional analysis

Template:Functional analysis has been largely expanded since several years by Mgkrupa and Selfworm. Its size has more than doubled. The result provides a huge and almost indiscriminate collection of links, often shortened in a confusing way for saving some space (for example, one of the links is displayed as "Grothendieck"). IMO, searching an article in this template is not easier than searching it by any other standard mean, and its present state is absolutely not useful. This template must be dramatically reduced and restructured for being useful for non-specialists. I would be tempted to nominate it for deletion per as WP:TNT, but I am not a specialist of this area. Some other advices are thus needed. (The template's talk is empty). D.Lazard (talk) 15:04, 19 April 2020 (UTC)

An example of the silliness of the template is that it contains a link to List of Banach spaces, and, nevertheless, the articles of this list appear in the template, and are distributed in several sections. D.Lazard (talk) 15:18, 19 April 2020 (UTC)

I agree that a purge of items in this template would benefit those new to those field, but make it less useful for those who are more knowledgeable in it. We need a solution that will make the template useful for all people.Mgkrupa (talk) 15:53, 19 April 2020 (UTC)

We could greatly reduce the size of this template by splitting it up into sub-templates like with Template:2019–20 coronavirus pandemic. Say by placing

• all items that relate only to Hilbert spaces (and not more generally to Banach spaces) into their own sub-template,
• all other items that relate only to Banach spaces (and not to general TVSs) into their own sub-template,
• all items that do not require a topology (e.g. radial set) into their own sub-template
• all items related to bornology (i.e. bounded sets) into their own sub-template,
• all items related to nuclear spaces/operators in their own sub-template,

and so forth.Mgkrupa (talk) 15:53, 19 April 2020 (UTC)

I was thinking something like this: User:Mgkrupa/Functional analysis proposal. Mgkrupa (talk) 13:14, 20 April 2020 (UTC)

This is much better. However, if people add to this new template structure all related items, it may become as awful as the current version. IMO, such a navbox is not useful for experts of the subject; so there is no need to include in the navbox the narrow subjects that are interesting only for experts. Also it seems not useful to mention articles that are easily found as links in other articles. For example, most specific spaces that are listed in List of Banach spaces dot not require an entry in this template. In summary, we are faced to the difficult compromise between exhaustion and usefulness. D.Lazard (talk) 15:39, 20 April 2020 (UTC)

I don’t have a concrete proposal but Template:Lie groups, I think, has a right balance; not too many not few items and also uses the “collapse” feature. I am sure we can aim for something similar here (and am willing to spend time no one else is interested). —— Taku (talk) 18:49, 20 April 2020 (UTC)

Gamma function

Would someone be willing to take a look at the recent edits at Gamma function? There's an editor insisting on adding what appears to be (poorly written) OR; I've started a talk page thread but I'm at 3RR and don't see how I can explain it any more clearly. Thanks, –Deacon Vorbis (carbon • videos) 01:21, 24 April 2020 (UTC)

I've warned the user for edit warring. They are past 3RR, but I'm going to give them one last bit of good faith to stop and discuss it. --Kinu ^t/_c 01:25, 24 April 2020 (UTC)

Draft:Copy Detection Pattern

I know that this is a very active project, and so I expect that someone will respond to this request. Can someone either please review this draft, Draft:Copy Detection Pattern, and advise me whether to accept it, or advise me where to request a review of this draft? It appears to me to be reasonable, and I don't see anything obviously wrong with it, so that my thought is to accept it, but I would prefer to have another editor review it, perhaps one who hasn't forgotten as much mathematics as I have. (I still know algebra and calculus, but I learned them in high school.) Robert McClenon (talk) 22:13, 23 April 2020 (UTC)

I am not sure mathematics is quite the right topic area, but I also don't know who else to suggest instead! (Maybe, this just reflects how far it is from things I know things about.) All that said, I looked it over and I didn't see any problems that would prevent acceptance. --JBL (talk) 22:33, 23 April 2020 (UTC)

Another reviewer accepted it. I would have accepted it but wanted another opinion, so we agreed, and that is all right. The author of the article appears to be an academic with knowledge about the subject, and so is a welcome addition to Wikipedia. Robert McClenon (talk) 00:20, 26 April 2020 (UTC)

Systems of polynomial inequalities

This section describes a method for solving systems of polynomial inequalities, but it provides no references, so I'm not sure if it's accurate. Which references should be cited in this section? Jarble (talk) 18:18, 27 April 2020 (UTC)

I have replaced the section by a link to the general algorithm for the problem. D.Lazard (talk) 18:36, 27 April 2020 (UTC)

Disambiguation help

There was a recent move that reshuffled the naming scheme of articles on the topic of range, leading to a large number of links from article-space to the disambiguation page range (mathematics). Most of these have been resolved, but maybe someone else would like to take a look at the few that remain; they are listed here. Thanks, JBL (talk) 21:56, 29 April 2020 (UTC)

May 2020

Edit war at Unknown

There's a disagreement that could use some more eyes at Unknown (dab page)). See also Talk:Unknown#Ordering of sections. D.Lazard (talk) 14:56, 3 May 2020 (UTC)

Auxiliary normed space

The entire initial section of the new article with this title is as follows:

Two methods of constructing normed spaces were systematically employed by Alexander Grothendieck to define nuclear operators and nuclear spaces.

Could someone who know something about the topic and about Wikipedia usages change this to something appropriate? Michael Hardy (talk) 19:48, 28 April 2020 (UTC)

Hi! I added some introductory sentences giving a quick overview of the two methods of constructing auxiliary normed spaces. Best wishes.Mgkrupa (talk) 00:07, 4 May 2020 (UTC)

Hyperoperations, User:Ferctus

Ferctus (talk · contribs · deleted contribs · logs · filter log · block user · block log) They've just recreated some pointless redirects (octation, heptation) that have recently been deleted, are adding pointless cruft to articles like tetration and pentation, etc. Some more eyes would be welcome. --JBL (talk) 21:19, 7 May 2020 (UTC)

I tried to prune the cruft back and was reverted minutes later without explanation [5][6]. XOR'easter (talk) 23:00, 7 May 2020 (UTC)

Seems to have sorted itself out. --JBL (talk) 00:59, 8 May 2020 (UTC)

System of differential equations

As we can see, "system of differential equations" is a red link. Is this topic really missing or should it be redirected? (In contrast, system of polynomial equations does exist, unsurprisingly I suppose). —- Taku (talk) 08:02, 5 May 2020 (UTC)

The topic seems distributed. We have ordinary_differential_equation#System_of_ODEs, matrix differential equation and partial_differential_equation#Systems_of_first-order_equations_and_characteristic_surfaces. Perhaps a disambiguation page or broad concept article/stub would be appropriate? --{{u|Mark viking}} {Talk} 10:59, 5 May 2020 (UTC)

System of equations is already such a stub/broad-concept article. system of differential equations could redirect there. D.Lazard (talk) 11:49, 5 May 2020 (UTC)

A redirect seems like a subpar solution; the readers interested in this topic will surely be unhappy with system of equations (as there are some many specific aspects in the differential case). I also noticed differential system redirects, which seems also problematic. I have therefore started System of differential equations. -- Taku (talk) 23:54, 5 May 2020 (UTC)

A related question: is the article "Matrix differential equation" redundant? I mean, should it be merged with ordinary differential equation? -- Taku (talk) 00:18, 6 May 2020 (UTC)

As one might expect, a matrix differential equation is just a way to represent a system of differential equations. It might be worth merging it to system of differential equations. — MarkH₂₁^talk 15:21, 6 May 2020 (UTC)

I get what you mean but, despite the article title, the bulk of the article is simply about linear ODE; especially how to solve it using linear algebra (which is important and should be discussed in the ODE article, in my opinion). It ignores PDE entirely; in fact this article seems an instance where (matrix) "differential equation" means linear system of ODEs, similar to the case when a undergraduate course named "introduction to diff equ" refers to linear system of ODE. -- Taku (talk) 04:01, 8 May 2020 (UTC)

Yeah, I think the content can be merged to both System of differential equations and Ordinary differential equation#System of ODEs since the existing content is pertinent in both places, but the title should redirect to System of differential equations in the end since the title refers to systems of PDEs as well. — MarkH₂₁^talk 04:06, 8 May 2020 (UTC)

Help at Carrying capacity (K)

Not really my field (population dynamics), but what was written earlier was total bunk. I deleted almost all the polemics about human overpopulation, and am trying to rewrite the article in the way I was taught this stuff decades ago. Which involved a lot of math...

I'm wondering if the main two equations (or at least one) I copied into the text could be rewritten so that K= yaddayadda. Is that even kosher (with regards to sourcing)?

After the introductory maths, I'd then like an example with a graph, the same I had back in the day, population of bacteria in a petridish, where the pop. reaches K in a sigmoid curve and then falls in the same curve (what's that called, bell-shaped?).

Could someone also vet what I've done so far? Outside of the standard application, environmentalists claim K is not actually a constant, but a variable which is determined by N. I spent all night thinking how that could work mathematically ... is this just patent nonsense? Cheers, Leo Breman (talk) 09:25, 9 May 2020 (UTC)

About the last point: In mathematics the distinction between variable and constant is essentially context dependent. As far as I understand what you have written in the article, K is a "model constant" or empirical constant, that is a quantity that cannot be measured, but is chosen for a best fit between a model and the reality. That is in this sense that K depends on N and its variation.

About "K= yaddayadda": The definition of K can be viewed as a generalized implicit equation. In general, an implicit equation cannot be explicitly solved. I suspect that it is the case here. In any case, if it is not solved in the literature, providing a solution would be WP:OR, and could not be given here. D.Lazard (talk) 10:37, 9 May 2020 (UTC)

Thanks, that actually makes a lot of sense. You're saying K is approximated from the change in N, not actually measured. But that is not exactly what was being said earlier, which was that K decreases as a function of when N nears K... but it turned out that the reference used did not say that at all (didn't even mention the subject matter), so I deleted all that. About "K= yaddayadda": Okay, too bad. Now you mention it, with the bacteria stuff we derived K and r from the experiment. Hey, useful, thanks, Leo Breman (talk) 11:34, 9 May 2020 (UTC)

Redirects for discussion

There are three mathematics-related redirects for discussion: ⋾, V* and 4-sphere. XOR'easter (talk) 18:11, 9 May 2020 (UTC)

Bottema's theorem: article draft

Dear WikiProject Mathematics, I just wrote an article draft for Bottema's theorem: Bottema's theorem. Could please have a look at it and inform me if it is acceptable? Any improvement is of course very much appreciated. A last question: can I join the WikiProject Mathematics? Is there an official way to join the project? Best Regards; Count Von Aubel (talk) 18:32, 9 May 2020 (UTC)

@Count Von Aubel: There’s no formal process for joining the WikiProject! Just chime in whenever you want :)

You can also add the user box {{User WikiProject Mathematics}} to your user page if you want. — MarkH₂₁^talk 18:38, 9 May 2020 (UTC)

You can also add yourself to Wikipedia:WikiProject Mathematics/Participants. —David Eppstein (talk) 18:43, 9 May 2020 (UTC)

Many Thanks! Count Von Aubel (talk) 18:52, 9 May 2020 (UTC)

Magic this and that

If someone wants to clean out some exceptionally crufty recreational mathematics articles, have a look at Magic hypercube, Magic hyperbeam, and Nasik magic hypercube. Between the three of them, there are enough good sources for one decent encyclopedia article, but it won't look anything like the first two articles I've linked. (Nasik magic hypercube is in better shape.) I started on Magic hypercube, then got discouraged by the magnitude of the cruft. --JBL (talk) 16:08, 17 May 2020 (UTC)

Associate Legendre Functions with meaningful learning expansions

I did many mathematical equations and formulas they are still not perfect as I use them much [move to various places]but I can retype them [ i may have them in eletronic version as well]and improve [especially meaningul expansions of particular letter. Preferably they would be in meaningful pair of [noun+verb] which would be easier to remember and implement. Here2,3 is associated legendre function and here meaningful expansions. 2 Fermiparadox97 (talk) 15:50, 14 May 2020 (UTC)

I am sorry. But these appear to be original research (see WP:OR) which is not allowed in articles and usually not even tolerated on talk pages. You could put it into your WP:Sandbox and thus have it in a more readable form. JRSpriggs (talk) 20:24, 14 May 2020 (UTC)

"Not even tolerated on talk pages"? I hadn't heard of that. Michael Hardy (talk) 18:43, 16 May 2020 (UTC)

Probably WP:NOTFORUM is the relevant thing. --JBL (talk) 16:09, 17 May 2020 (UTC)

"Not even tolerated" is perhaps slightly too strong; "usually frowned upon" might be closer. As JBL points out, talk pages are supposed to be for discussing how to improve the articles they're attached to, not for more wide-ranging discussion of the subject matter. Of course, there's going to be some gray area between those. XOR'easter (talk) 16:18, 17 May 2020 (UTC)

Old Noether photo

If anyone has useful knowledge about the early publication history of the main photo in our Emmy Noether article, File:Noether.jpg, it would be a useful contribution to the discussion at Commons:Commons:Deletion requests/File:Noether.jpg. Without suitable information about its provenance, the file seems headed for deletion on commons as it may not be public domain under German law (it may be possible to save a copy locally on en.Wikipedia.com, though, as it is likely to be public domain under US law and if I remember correctly that's the one that's considered controlling for en). —David Eppstein (talk) 01:24, 19 May 2020 (UTC)

Not directly related, but this reminds me of when a book about Emmy Noether had accidentally used a photo of a different woman for the cover. — MarkH₂₁^talk 04:49, 19 May 2020 (UTC)

Fascinating! —David Eppstein (talk) 05:02, 19 May 2020 (UTC)

Draft:Centromerick numbers

Can someone please take a look at this draft and see if they can explain what centromerick numbers are?

I have forgotten all of the mathematics that I learned in college, but I have not forgotten the mathematics that I learned in high school, through introductory calculus, and I have not forgotten the mathematics that I learned in middle school, and this appears to be number theory, which is advanced arithmetic. I don't understand this draft, and I think that this draft is not capable of being understood in English. Maybe the Russian is capable of being understood if one can read Russian. Robert McClenon (talk) 23:29, 22 May 2020 (UTC)

Has all the signs of pure crankery. --JBL (talk) 23:47, 22 May 2020 (UTC)

Thank you, User:Joel B. Lewis. Robert McClenon (talk) 20:03, 25 May 2020 (UTC)

I've rejected the paper because it is incomprehensible. Robert McClenon (talk) 20:08, 25 May 2020 (UTC)

People reverting my edits

Hi, probably because I put Möbius_function instead of From someone reverted my edits. Then the same user became nuts and other users came too.

There is a huge problem with users reverting other's edits.

Those people clearly don't understand anything about the edit itself. This is not acceptable to be insulted in such a way for several days when just adding a formula on an article. https://en.wikipedia.org/w/index.php?title=Euler%27s_totient_function&action=history

This is of course not about me, I don't care at all, I'm just upset because I am a wikipedia user and a good mathematician/student/teacher and obviously I want to be allowed to do a few edits by year without having any interaction with those harmful people.

You should detect the number of revertions made by each user and block, for a month, anyone who is doing too many such harmful reversions.

Reuns (talk) 02:05, 27 May 2020 (UTC)

@Reuns: The primary issue is that you are edit warring. Repeatedly reverting to add your edit back because you think others don’t understand is not allowed. Go to the talk page and discuss if you think someone doesn’t understand your edits.

The underlying issue is not the formula. It’s the bad piped link. Read WP:SUBMARINE as others have directed you to. Also read WP:SURPRISE. They’re commonly accepted standards of writing. — MarkH₂₁^talk 02:16, 27 May 2020 (UTC)

@Reuns: I acknowledge that you have removed the link from your last edits. It remains that beginning the statement of a theorem by a proof of it consisting in two huge formulas is a very bad idea, which is confusing for most readers (most will not read the sentence until the statement of interest). I agree that the current statement lacks of some explanations, but two formulas are not an explanation. So, as Wikipedia is a collective work, a discussion on the talk page is needed for finding collectively the best formulation. Before getting a consensus, the disputed section must not be changed. See WP:BRD for details about this standard process of Wikipedia. D.Lazard (talk) 08:12, 27 May 2020 (UTC)

Redirect for deletion: Steriruncitruncated 6-demicube

Can anyone explain why Steriruncitruncated_6-demicube is a redirect to Pentic 6-cubes? Vote in the discussion here: Wikipedia:Redirects for discussion/Log/2020 May 28#Steriruncitruncated 6-demicube. —Naddruf (talk ~ contribs) 02:51, 29 May 2020 (UTC)

@Naddruf: Probably because there is a section Pentic 6-cubes#Pentisteriruncicantic 6-cube, and this would be a 6-demicube kind of analogue? Just a guess. — MarkH₂₁^talk 08:19, 29 May 2020 (UTC)

Generalized minimal residual method

I was alerted to this edit offwiki (someone trying to program the algorithm). Was the edit correct generally, and specifically, is r_0 = b correct if x_0 = 0 (rather than r_0 = -b)? --Izno (talk) 20:40, 28 May 2020 (UTC)

Formally it should be -b but it does not seem to change anything regarding the algorithm as the only thing that counts is the subspace generated by $r_{0}$. Anyway in Saad's book he seems to take $r_{0}=b-Ax_{0}$ so I put this convention in the article's text. This should probably be rewritten more in depth by somebody who is more familar with the subject or has more time than I do to get a better presentation. jraimbau (talk) 11:19, 29 May 2020 (UTC)

Jun 2020

A bit of help needed on Draft:Virasoro group

This article is really technical, and kind of reads like an essay (e.g. "this article will..."). However, this is a notable topic, so I'd like someone good in group theory (Lie algebras) to help me out. Eumat114 formerly TLOM (Message) 05:20, 2 June 2020 (UTC)

I can spend some time on summarizing the details. There’s also a bit of copyediting with the tone and bolding that needs to be done. — MarkH₂₁^talk 07:43, 2 June 2020 (UTC)

@Eumat114: I did some work on it. It could still be improved, but it's not so WP:TEXTBOOK-like anymore. — MarkH₂₁^talk 23:52, 2 June 2020 (UTC)

Plural titles

Categories such as Category:6-polytopes and Category:7-polytopes have a whole lot of plural titles, where singular would be the WP way per WP:PLURALS. Many (perhaps all) created by @Tomruen: Is there any objection to a bulk fix back to singular? Dicklyon (talk) 20:43, 28 May 2020 (UTC)

I'm not going to defend TR's preferred article style, nomenclature, sourcing standards, or the independent notability of these topics, but articles such as Runcinated 6-simplexes appear to be about multiple distinct related topics (the Runcinated 6-simplex, Biruncinated 6-simplex, Runcitruncated 6-simplex, Biruncitruncated 6-simplex, Runcicantellated 6-simplex, Runcicantitruncated 6-simplex, and Biruncicantitruncated 6-simplex), hence the plural. So I think fixing this mess may be more than a simple rename. And may face some pushback from TR. —David Eppstein (talk) 20:49, 28 May 2020 (UTC)

I understand there's more than one kind of runcinated 6-simplex, but that's not usually a reason for use plural titles. Dicklyon (talk) 00:12, 29 May 2020 (UTC)

I have no preference if an automated conversion can be done. Tom Ruen (talk) 21:03, 28 May 2020 (UTC)

Automation, maybe; preparing the list is the hard part. Doing it in bulk "by hand" is also possible. Dicklyon (talk) 00:12, 29 May 2020 (UTC)

WP:PLURAL says that "Articles on groups or classes of specific things" is an exception to the rule of singular titles. This is the reason of the plural of Trigonometric functions, and clearly also of Runcinated 6-simplexes. So, it is possible that all these plural titles result simply of the application of WP rules. In this case, they must be kept plural. D.Lazard (talk) 07:56, 29 May 2020 (UTC)

From the leads with singular (In six-dimensional geometry, a runcinated 6-simplex is a ...), the articles are pretty clearly on the items on the class, not the classes themselves, unlike Trigonometric functions, where the lead is plural and about the class (though really, it could also be done singular; the exception is for cases where the singular makes less sense). See many singular examples such as A7 polytope and Cross-polytope, which is the normal style. Dicklyon (talk) 19:16, 31 May 2020 (UTC)

@D.Lazard: Let us know if you want to object or not. I can apply for a bot to do these moves if they're uncontroversial. Dicklyon (talk) 20:21, 31 May 2020 (UTC)

Here are the articles I found (with queries like this): Rectified_5-cubes, Steric_7-cubes, Rectified_9-cubes, Runcic_6-cubes, Runcic_7-cubes, Runcic_5-cubes, Pentic_7-cubes, Truncated_5-cubes, Rectified_6-cubes, Rectified_8-cubes, Rectified_7-cubes, Truncated_7-cubes, Truncated_6-cubes, Cantellated_6-cubes, Hexic_7-cubes, Steric_6-cubes, Steric_5-cubes, Truncated_8-cubes, Runcinated_5-cubes, Cantellated_5-cubes, Rectified_10-cubes, Runcinated_6-cubes, Cantellated_7-cubes, Stericated_6-cubes, Runcinated_7-cubes, Stericated_5-cubes, Pentellated_6-cubes, Pentic_6-cubes, Stericated_7-cubes, Pentellated_7-cubes, Hexicated_7-cubes, Hexicated_8-simplexes, Rectified_6-simplexes, Pentellated_8-simplexes, Truncated_5-simplexes, Truncated_7-simplexes, Heptellated_8-simplexes, Truncated_6-simplexes, Cantellated_6-simplexes, Rectified_8-simplexes, Rectified_7-simplexes, Truncated_8-simplexes, Rectified_10-simplexes, Rectified_9-simplexes, Runcinated_5-simplexes, Runcinated_8-simplexes, Cantellated_5-simplexes, Stericated_8-simplexes, Cantellated_8-simplexes, Runcinated_6-simplexes, Cantellated_7-simplexes, Stericated_6-simplexes, Rectified_5-simplexes, Runcinated_7-simplexes, Stericated_5-simplexes, Pentellated_6-simplexes, Stericated_7-simplexes, Pentellated_7-simplexes, Hexicated_7-simplexes, Runcinated_6-orthoplexes , Rectified_5-orthoplexes , Cantellated_5-orthoplexes , Truncated_6-orthoplexes , Truncated_5-orthoplexes , Rectified_9-orthoplexes , Rectified_7-orthoplexes , Truncated_7-orthoplexes , Truncated_8-orthoplexes , Cantellated_7-orthoplexes , Rectified_6-orthoplexes , Rectified_8-orthoplexes , Cantellated_6-orthoplexes , Runcinated_5-orthoplexes , Pentellated_6-orthoplexes , Rectified_10-orthoplexes , Stericated_6-orthoplexes , Runcinated_7-orthoplexes , Stericated_7-orthoplexes , Hexicated_7-orthoplexes , Pentellated_7-orthoplexes . I don't see others besides cubes, simplexes, and othroplexes, but I may be overlooking some. Dicklyon (talk) 19:23, 31 May 2020 (UTC)

I remain convinced that the exception of WP:Plural applies here. IMO, this is not the main issue of all these articles (see below), and changing their titles to singular would be a waste of time. Nevertheless, I'll not formally object if someone is willing to spent time for this change. By the way, A7 polytope, although having a singular title, is devoted to a finite set of specific polytopes. It is amazing that this set is asserted in the first sentences of the articles to have 71, 135, and 63 elements, without any indication on the reasons of these changes of numbers!

The main issue of these articles is that they are a WP:walled garden, as all together they have very few incoming links (List of polytopes, and regular polytopes). This is difficult to merge them, because of the number of pretty figures. So, IMO, they must be moved as subpages of List of polytopes. This would be a much more useful renaming project. D.Lazard (talk) 11:49, 1 June 2020 (UTC)

I don't think we do subpages in article space, but I'm listening if people have alternative ideas. The above list is something I can handle "by hand" in a few days, which might be easier than getting bot approval to do it. Dicklyon (talk) 06:08, 2 June 2020 (UTC)

Please comment on my bot request at Wikipedia:Bot_requests#Move_205_mathematics_pages_to_singular_title if you care about this. Dicklyon (talk) 22:56, 4 June 2020 (UTC)

Never mind, I canceled/reverted my bot request, as this seems not as simple as I thought, since the singular redirects to a specific member of the plural class article in many cases. I'd rather let the plurals slide than bother trying to find a better way to do it at this point. Carry on... Dicklyon (talk) 04:00, 6 June 2020 (UTC)

Wikipedia:Miscellany for deletion/Draft:MOVE IT Math (2nd nomination)

Hi all,

I have started an MfD on a program that I don’t think is notable enough for Wikipedia (there are too many of programs like it). But that’s just my judgement and I invite editors who have opinions on the matter to the discussion. —- Taku (talk) 07:32, 7 June 2020 (UTC)

Unit circle

I have been having some disagreements with an editor at Unit circle (not a page that many here would have on their watchlists). He does not seem to be able to see the errors he has committed nor is he able to discuss the topic meaningfully. Extra eyes on the page would be appreciated and perhaps someone else can get through to him, as I seem to have failed.--Bill Cherowitzo (talk) 19:01, 8 June 2020 (UTC)

Analysis of vector-valued curves

Could some expert in analysis have a look on this article recently created by Mgkrupa. I have some problems with it that may or may nor be caused by my lack of knowledge in analysis.

• Reading the title, I have no idea about what is or should be the content of the article.
• Is article's title a commonly used phrase, or is the title WP:OR?
• Is the article a content fork? In other terms, is the article content covered or not in other articles?

These are the questions about the article as a whole. Looking on the details, it seems that a lot of work is needed for making the article comprehensible. D.Lazard (talk) 19:30, 7 June 2020 (UTC)

The article just looks like an attempted introduction to various topics in functional analysis on which we already have articles, and isn’t even referenced. I’m moving it to draftspace for now. — MarkH₂₁^talk 20:42, 7 June 2020 (UTC)

So, the article title looks problematic; is it really standard one? As far as remember Rudin doesn't use that term in his "functional analysis" text. As far as I can tell, the draft is about (differential and integral) calculus on topological vector spaces, which is a perfectly valid encyclopedic topic (e.g., the early edition of Rudin's text had a chapter on that topic, I believe.) How about renaming it to something like "calculus on topological vector spaces"? Fixing the issues, it should be ok to move it back to mainspace, in my opinion. -- Taku (talk) 22:52, 8 June 2020 (UTC)

Cap set WP:CONTENTFORK

Can someone explain to me why cap set needs to be separate from the new sort-of-article (really a proof masquerading as an article) Exponential bound on capsets? It's not like the main article is so overburdened with content that it needs WP:SUMMARY style. —David Eppstein (talk) 03:58, 9 June 2020 (UTC)

I am afraid I don't understand. Looking at the article history, you originally rejected the proof as a bad fit for cap set [7], so user ProveStuff created a new article. Now you want to merge the two? I think a merge or a selective merge would be OK, depending on the appropriate level of detail in the proof. --{{u|Mark viking}} {Talk} 04:19, 9 June 2020 (UTC)

I still think it's badly written and unencyclopedic, but that doesn't mean that putting it into a standalone article makes it better. —David Eppstein (talk) 04:48, 9 June 2020 (UTC)

• The article was dedicated solely to the proofs of a theorem that by itself doesn't warrant its own article. The theorem itself could be covered in cap set, but it's not even one of the major theorems in this particular problem on cap sets, so it wouldn't really be due WP:PROPORTION to cover it or its proofs in such detail anywhere.
  I've converted the article into a redirect to Cap set#Cap set problem while only giving the statement of what Tao proves in his blog post. Even if there is consensus to cover the proofs in some form (for which there is no consensus right now), it should be at cap set rather than in its own article. — MarkH₂₁^talk 05:27, 9 June 2020 (UTC)

I'm responsible for moving the draft to mainspace (I was not aware the draft was a content fork). I was not convinced that the result in the draft is notable enough for a standalone article, but was also not convinced the draft needs to be deleted without a proper review.

As for the basic question of whether we should cover the proof like that: quite generally, Wikipedia articles are essentially duplicates of existing literatures (in fact, that's requirement). We don't just mention the existence of some calculus computations and send the readers to textbooks in calculus for them to see but we do reproduce some of such; that's part of the mission of math articles in Wikipedia, I think. As for this particular one? I am not too sure; I defer the judgement to the others (and moving the draft to mainspace will facilitate that). -- Taku (talk) 08:04, 9 June 2020 (UTC)

Variations on open sets

In April, Mgkrupa produced a number of stubs drawn from the Encyclopedia of general topology on minor definitions relating to openness: Preopen, Semi-preopen, Semi-open, Α-open, B-open, Δ-open, Θ-open (and maybe others that I haven't found). Each article consists of a one- or two-sentence definition, together with a statement of how it relates to the other definitions. I personally find it hard to imagine any of these ever becoming a real encyclopedia article; I tentatively propose that they be merged into a single article (maybe "list of openness properties"; better suggestions welcome), unless someone is very confident that there's lots of encyclopedic material waiting to be added to at least two of them. (If there's only encyclopedic content to be had on one of them, then I propose all the others be merged to that title.) Thoughts? --JBL (talk) 16:17, 8 June 2020 (UTC)

Are there any sources other than the cited Hart (2004)? It's almost as if the original editor is copying that encyclopedia into Wikipedia. (For what it's worth, I have a Ph.D. in topology and I've never heard of most of these. But then I'm on the geometric side of topology, my experience is not universal, I'm not a reliable source, etc.) Mgnbar (talk) 17:37, 8 June 2020 (UTC)

I agree with JBL suggestion. By the way, the same user has largely expanded the navbox Template:Functional analysis. Generally, I am not fan of navboxes, because they are not useful for the searches that I need. Nevertheless, I find this navbox too large (and covering too much subjects) for being useful to anybody. I have not a clear opinion on what should be done with this template. Do the other editors have an opinion? D.Lazard (talk) 17:45, 8 June 2020 (UTC)

Ditto on JBL's suggestion. As to these navboxes ... I too have had some problem with them. Having Linear algebra as a subtopic this editor has stuck this template on several Linear algebra pages. I have removed a few as not being relevant to the page, but I'm sure there are many more inappropriate placements.--Bill Cherowitzo (talk) 18:55, 8 June 2020 (UTC)

(I think I said this before, but) I too find the nav-box too large. I myself like a navbox; when done right, they are very useful (e.g., Template:Lie groups) and I suspect many readers use them. The problem with this one is that it essentially duplicates List of topics in functional analysis. Yesterday I have started Draft:Glossary of functional analysis, in part to move some items in the navbox over there. -- Taku (talk) 22:58, 8 June 2020 (UTC)

Also, I have created a proposed new version of Draft:Template:Functional analysis. I think this version is much more useful. -- Taku (talk) 23:41, 8 June 2020 (UTC)

That’s the largest navbox that I’ve seen so far! Replace it with the draft as soon as possible.

Even the old version (February) was too large, at about half the size of the current one— MarkH₂₁^talk 03:49, 9 June 2020 (UTC)

Ok. I have replaced the template with the new version; please do expand it or make other changes as needed. -- Taku (talk) 22:19, 9 June 2020 (UTC)

Glossary of topology already exists. --Trovatore (talk) 23:04, 8 June 2020 (UTC)

Yes, the glossary is the great (and standard) way to cover definitions that do not merit independent articles. -- Taku (talk) 23:41, 8 June 2020 (UTC)

Ok, great. If I get up the energy I will move the seven I linked to above into the glossary, but I invite anyone else to do it first! --JBL (talk) 23:57, 8 June 2020 (UTC)

I have merged all of them to Glossary of topology. --JBL (talk) 21:01, 10 June 2020 (UTC)

Log Quaternions

I started a few days ago digging for information about the logarithm of quatnerions, and it's use. The page(s) here Wikipedia Quaternion Article, wikipedia Qatuernions and spactial rotations, barely mention them except the express the math of the operation.

Here is my test project, started to test this new-found knowledge, and other references at the bottom I've read. https://github.com/d3x0r/STFRPhysics#frame-computation-using-dual-log-quaternions

To summarize quickly, given that the rotation quaternions input (or projected from natural-log mapping) is a unit vector, the conjugate and reciprocal are the same. This means that PQ = P with Q's rotation added. QP = Q with P's rotation subtracted. or PQ = PQ and QP = P/Q. The order of the operation in natural quaternion space as multiplication is represented in natural log-quaternion space as a subtraction instead of addition; that is instead of changing the order of the operands, just subtract instead of adding.

This can be quickly visualized in the complex number case, that A * B = the rotation of A + rotation of B. where B * A can also be seen as subtracting from 1 and getting the rotation of A minus the rotation of B.

The construction of a log-quaternion

 // pass the same parameters of a direction normal and angle of rotation to make a log quaternion
 // ... without taking the log of a quaternion.
 function logQuaternion(theta, normal ) { 
   return [ Math.log( theta ), normal.x*theta, normal.y * theta, normal.z * theta ] /* w,x,y,z */ 
 }

It can be seen simply from the construction, that the angles of ln space are really simply the angles simultaneously around x, y and z axis. The exp() function takes the angles specified and normalizes them to -1 to 1 when converting to a quaternion; collapsing any accumulated rotation information.

Now see, I would love to just come back to the above mentioned articles and see a nice section on normalizing the log-quaternion to prevent radical overflows; it can certainly be translated to a quaternion and back, and lose any overflow information.

I suspect, also, that any errors between the rotations of the two systems are the fault of working in quaternion unit-vector space which truncates partial overflows, that a later subtraction might bring back to 137 instead of -17.

The accumulators of a log-quaternion vector are basically a long tape of potential angles input, without being auto modulated with within range.

Plus. The 'multiplication' or 'application' of one rotation to another for summing through a chain is a simple 4-vector addition or subtraction; the application of a log-quaternion can be combined with its exp() operation and still be cheaper than a full translation with quaternion multiplication....

So; I can't fathom why this simple method isn't already the most prominent, and is instead relegated to a dark corner and the quote 'multiplication is not commutative'... Yes; I agree, the result of multiplication in quaternion space is not; and this is reflected in tangent space by subtracting instead of adding; which means that the operation in real space actually resembles division, and not a re-ordered multiplication.

D3x0r (talk) 21:04, 10 June 2020 (UTC)

References

Was Simulated Annealing developed in 1970?

A new user has been changing our article on Simulated Annealing to state that it was developed by Martin Pincus in 1970, some 13 years before it is commonly understood to have been developed by Scott Kirkpatrick. More eyes would be appreciated - MrOllie (talk) 19:58, 12 June 2020 (UTC)

Jacob Barnett

I think he has been of interest to members of this Wikiproject in the past. A new draft has been submitted to AfC. --JBL (talk) 12:17, 12 June 2020 (UTC)

Nothing has changed since the article on him was deleted and the attempt to recreate an article on him disguised as an article about a book was also deleted. The press coverage of him was superficially impressive but astonishingly poor upon even slightly closer inspection. As for his scientific career, his publication record is quite paltry and falls far short of WP:PROF. Three papers and a poster is a little less than what my department would expect from a student about to defend their PhD thesis, for example. So, we don't have grounds to write an article about him either as a child prodigy or as an adult physicist. XOR'easter (talk) 16:22, 12 June 2020 (UTC)

Thanks; I left a comment for the future AfC reviewer there, and pointed them back here. --JBL (talk) 20:13, 12 June 2020 (UTC)

Integral operator

Please can a subject expert look at the remaining incoming links to disambiguation page Integral operator, and divert them to appropriate articles? Thanks, Certes (talk) 01:13, 14 June 2020 (UTC)

I have edited Integral operator for adding a missing item, and fixing the description of the two other items, that described wrongly the linked subject. I had also to rewrite the lead of the linked article Integral transform, that was completely wrong.

IMO, this article must not be a dab page, but a broad concept article, as all items are special cases of a single concept. I'll be bold, and making this transformation. This will avoid the boring work asked for in the preceding post. D.Lazard (talk) 11:07, 14 June 2020 (UTC)

Thank you, D.Lazard. I think that's the insight we were missing. If I was trying to choose between two inaccurate definitions when the most appropriate destination was missing, it's hardly surprising that I didn't get very far. Certes (talk) 12:04, 14 June 2020 (UTC)

Talk:Π#Redirect_dispute

For the interested, what should Π redirect to? Gråbergs Gråa Sång (talk) 17:50, 14 June 2020 (UTC)

African-American mathematicians

Category:African-American mathematicians has been nominated for deletion/upmerging. See Wikipedia:Categories for discussion/Log/2020 June 13#Subgroups of African-American scientists for the discussion. —David Eppstein (talk) 20:25, 16 June 2020 (UTC)

Joint continuity

In Normed vector space, the phrase "jointly continuous" is used (for addition and scalar multiplication) without definition nor link. I have found a definition of "joint continuity" of a multiplication in Topological algebra. Linking the phrase there would be possible, although the definition and the usage do not refer to the same operations. But ...

I have never encounter this phrase elsewhere. Is it notable? If yes, where should be defined for being the target of a redirect? If not, is there another term for it or should we simply remove "jointly", and link to Function of several real variables#Continuity and limit? D.Lazard (talk) 18:25, 18 June 2020 (UTC)

The term is used in mathematics, for example in the intro of the paper [8] and this book on general topology. --{{u|Mark viking}} {Talk} 18:51, 18 June 2020 (UTC)

This is quite esoteric terminology. The definition is trying to say that the map $V\times V\to V$ is continuous with respect to the product topology on $V\times V$. This is both a clearer and more precise way of phrasing the definition.Tazerenix (talk) 18:54, 18 June 2020 (UTC)

I don't think it's esoteric at all. It's a very normal phrasing, generally understood even by people who don't do point-set topology on a day-to-day basis. --Trovatore (talk) 22:59, 18 June 2020 (UTC)

Extra eyes

Would someone mind taking a look at List of mathematical constants to see if they agree with my reverts of a couple recent additions? I'm at 3RR, and so I'm stuck. Thanks, –Deacon Vorbis (carbon • videos) 19:12, 8 June 2020 (UTC)

It is difficult to think of a less rewarding way to spend time than convincing someone not to include rational powers of small integers in List of mathematical constants. --JBL (talk) 19:19, 8 June 2020 (UTC)

What’s the inclusion criteria of the list? Restricting it to constants with their own articles might save a lot of time in general. — MarkH₂₁^talk 03:53, 9 June 2020 (UTC)

That sounds reasonable. At least a couple items on the list had articles that have been deleted, and it might be best to remove those. XOR'easter (talk) 17:20, 9 June 2020 (UTC)

Yeah, I was thinking along those lines as well, although I could conceivably see some entries without dedicated articles if they were at least discussed in sufficient detail in some other article. I was thinking about taking a closer look this evening. –Deacon Vorbis (carbon • videos) 17:44, 9 June 2020 (UTC)

I agree that clear inclusion criteria would be beneficial. --JBL (talk) 18:14, 9 June 2020 (UTC)

The article badly needs a rename, and the use of "mathematical constant" throughout the project should be rethought. People seem to be using it to mean interesting mathematical constants. But a mathematical constant doesn't have to be interesting. It doesn't even have to be definable. All it has to be is constant.

Maybe something like list of named numbers? --Trovatore (talk) 23:05, 18 June 2020 (UTC)

It’s a valid point, but I don’t know a good solution. Named numbers isn’t great either, since every number is effectively named under a loose interpretation of named, but a strict interpretation excludes things like Natural logarithm of 2. — MarkH₂₁^talk 23:27, 18 June 2020 (UTC)

List of named constants? though "named" seems a bit redundant. After all, for example, list of theorems is really a list of named theorems. -- Taku (talk) 03:59, 19 June 2020 (UTC)

We have also List of named differential equations. This is an article that I split out from Differential equation#Applications in August 2019, after the numerous additions by a single user of named differential equations (apparently, all that they have found in WP). I have chosen this title because List of differential equations seemed ambiguous for this content. So, List of named ... is fine for me. I would prefer List of named constants to list of named numbers for making clear that this is not a list of numerals, which, after all, are names for numbers. D.Lazard (talk) 08:54, 19 June 2020 (UTC)

How about List of especially notable complex numbers. JRSpriggs (talk) 15:24, 19 June 2020 (UTC)

I thought about using "notable" but I'm worried about mixing the WP-term-of-art sense of the word with its common meaning. To Wikipedians acting as Wikipedians, "notable" means something like "significant coverage in multiple reliable sources", where again "reliable source" is a term of art. We have to be careful to remember that that isn't how normal people (or even what passes for normal mathematicians) talk.

I do prefer "number" to "constant", for the reasons I gave. It's true that lots of "normal people" confuse "number" with "numeral", but that's not a case where we're being led astray by a term of art; it's just a case where they're wrong. --Trovatore (talk) 17:04, 19 June 2020 (UTC)

List of named constants seems the best of the suggestions so far, to me. I agree that we should avoid the term "notable", since its Wikipedian definition isn't quite the same as its meaning elsewhere. XOR'easter (talk) 18:22, 19 June 2020 (UTC)

I continue to object to "constant". --Trovatore (talk) 18:43, 19 June 2020 (UTC)

I'm having a bit of a hard time following your objection in this context. (Sorry! I'm probably just being a bit dense.) If a constant is named, then surely it is "interesting" — well, interesting to enough people that a name has become established. And, likewise, if a constant is named then surely it is "definable", at least to the point where it can be discussed, even if it's not algorithmically computable. XOR'easter (talk) 19:55, 19 June 2020 (UTC)

I don't think "constant" makes sense in this context. They're numbers. How exactly would they vary? Calling them "constants" is either redundant or a propagation of what I think is an inappropriate quasi-neologism. --Trovatore (talk) 20:55, 19 June 2020 (UTC)

The problem is not whether the title is correct from the point of view of mathematical logic. It is how people will understand the title. "Twenty two" and the number of the beast are named numbers and have not their place in this list. On the other hand, Euler's identity states "The identity also links five fundamental mathematical constants"; who is willing to edit the article for replacing "fundamental mathematical constant" by "fundamental number" or "fundamental mathematical number"? So, even if List of named numbers is more correct from a logical point of view, List of named constants must be preferred as less ambiguous, and clearer for most rreaders. Note also that either a section must be added for physical constants, or "mathematical" must be added to the title. D.Lazard (talk) 21:31, 19 June 2020 (UTC)

I don't think this sense of "constant" is really in use. I suspect it comes from Mathworld and Eric Weissstein. I have a strong aversion to helping propagate Mathworld neologisms. --Trovatore (talk) 22:20, 19 June 2020 (UTC)

I'm with Lazard that "constant" is an ok term; it's as opposed to a variable; pi is a (universal) constant even if it is just a number since it is independent of radius, volume or time, etc.. -- Taku (talk) 23:38, 19 June 2020 (UTC)

It's not a neologism. See examples from 2003, 1999, 1996, 1994, 1978 and 1877. XOR'easter (talk) 04:14, 20 June 2020 (UTC)

So nice list of attestations; got to give you credit (although your 1994 one is not an example of the sense being used here; you should strike that one). Still. What's wrong with "number"? --Trovatore (talk) 06:08, 20 June 2020 (UTC)

It is eplained in my previous post. D.Lazard (talk) 09:22, 20 June 2020 (UTC)

RfD

Hello, I wanted to notify the project of some RfD nominations for mathematical characters at Wikipedia:Redirects for discussion/Log/2020 June 24 I've started today. Currently, there is mostly a one-to-one discussion, which probably isn't that helpful. 1234qwer1234qwer4 (talk) 21:54, 24 June 2020 (UTC)

Category:Field (mathematics)

Recently, Category:Field theory was speedily renamed/moved to Category:Field (mathematics). (Field theory is a disambiguation page, and so the name of Category:Field theory is/was itself ambiguous.) However, to me the name Category:Field (mathematics) suggests a category collecting articles about specific fields, and I would prefer the name Category:Field theory (mathematics), to make it match with Category:Category theory, Category:Group theory, Category:Lattice theory, Category:Module theory, Category:Ring theory, Category:Semigroup theory and so on. Then again, "A foolish consistency is the hobgoblin of little minds." What do others say? – Tea2min (talk) 08:30, 25 June 2020 (UTC)

The term "field theory" (referring to the collection of mathematical statements around fields) is not commonly used, AFAIK (in contrast to ring theory and other theories). I therefore don't think a category "Field theory" is a good idea. Jakob.scholbach (talk)

We have a Glossary of field theory, haivng a category of field theory seems fine by me. --JBL (talk) 11:06, 25 June 2020 (UTC)

Field theory isn’t that rarely used. It’s often a term that’s applied when describing Galois theory for instance. I think Category:Field theory (mathematics) would be appropriate as a separate category from Category:Field (mathematics) (with the former containing the latter). — MarkH₂₁^talk 18:05, 25 June 2020 (UTC)

Category namers sometimes use the singular to classify articles about the general topic, and the plural for individual instances. Compare Category:Surname and Category:Surnames. I would expect to find articles about an individual field in Category:Fields (something). Certes (talk) 18:18, 25 June 2020 (UTC)

L2 norm

Please, discuss at WP:Redirects for discussion/Log/2020 June 24#L2 norm about the best target for the redirect L2 norm. D.Lazard (talk) 21:36, 25 June 2020 (UTC)

Philip Ehrlich

Notable? --JBL (talk) 14:54, 25 June 2020 (UTC)

I would tentatively say "no". He works in the philosophy of mathematics, so citation counts are going to be low and uninformative. I'd look for book reviews first, and a few do exist [9][10][11], but his two books were co-edited collections rather than treatises he authored himself. I'd hesitate to call that the kind of "body of work" that the notability guideline for authors asks for. Nor does it seem like those two co-edited collections attracted more than a baseline level of attention. I'm not seeing prestigious awards or journal editorships, either. XOR'easter (talk) 15:22, 25 June 2020 (UTC)

I cannot detect that this person passes the Average Professor Test stated in the guidelines. He is accomplished, but not clearly unusually so. Mgnbar (talk) 15:54, 25 June 2020 (UTC)

Thanks, both. It was PRODded a couple of years ago and declined for not convincing reasons -- eventually I may take it to AfD, if no one else gets there first. --JBL (talk) 16:42, 25 June 2020 (UTC)

Now at AfD. --JBL (talk) 16:07, 30 June 2020 (UTC)

Jul 2020

Mathbot?

Anyone know what has happened to Mathbot? No new additions to Mathlists since June 27. I seem to remember this type of thing happening a while ago as well.--Bill Cherowitzo (talk) 17:46, 1 July 2020 (UTC)

Possibly related User talk:Oleg Alexandrov#High WP 1.0 bot login rate. Oleg seems to be working on the bot to reduce the number of times it logs in. JRSpriggs (talk) 21:25, 1 July 2020 (UTC)

User:Mathbot/Changes_to_mathlists

This page stopped getting updated on June 27. What's going on? Who attends to this? Michael Hardy (talk) 22:26, 5 July 2020 (UTC)

I see: That's still User:Oleg Alexandrov. I'll drop him a note. Michael Hardy (talk) 22:55, 5 July 2020 (UTC)

Mathematics Drafts

There are 79 pages in Category:Draft-Class mathematics pages. Many of these seem to be pages which have been accepted but the review didn't correctly redirect the talk page as well. I'm trying to clear some of these.

In looking through the now accepted draft I came across Change of fiber a pretty sub-standard main space article. There might be some point in merging it somewhere or perhaps a delete or prod is in order.--Salix alba (talk): 18:12, 4 July 2020 (UTC)

It might be worth merging to Fibration. What's here now is just a short textbook-style treatment that's really not enough on its own. But the fact that May devotes a whole section to it gives me a little pause though. I'll do a little poking around later and see if maybe there's more than could be done with this. –Deacon Vorbis (carbon • videos) 18:43, 4 July 2020 (UTC)

What do people think of Draft:Eigencircle of a 2x2 matrix? Published in the well known Mathematics Magazine and The Mathematical Gazette, and seems to have a few references elsewhere.--Salix alba (talk): 19:18, 4 July 2020 (UTC)

I found and added to this draft category listing many more draft biographies of mathematicians. Most are junk but a few look likely to be notable. —David Eppstein (talk) 19:37, 4 July 2020 (UTC)

Is it really not related to Mohr's circle? How many useful ways of associating a circle to a 2x2 matrix can there be? It's hard to tell without detailed algebra, because the purpose/motivation of the eigencircle is never really explained. Mgnbar (talk) 12:04, 5 July 2020 (UTC)

I don’t want to discourage anyone but just want to mention that we also have Wikipedia:WikiProject Mathematics/List of math draft pages, which I think is better maintained (mainly by me) and tracks more math drafts. Maybe getting rid of this category altogether is simpler than cleaning it up. —- Taku (talk) 15:11, 5 July 2020 (UTC)

The advantage of the category is that people can easily add the drafts to the category just by placing the appropriate banner on the talk page. This work flow matches that for other projects and is included in the instructions displayed to editors. The work flow goes something like this:

• Editor goes to WP:AFC and hits the create article button.
• After a couple of dialog pages they then get to create their first draft.
• This created a skeleton page with the {{AFC submission}} template. In the 'Improving your odds of a speedy review' it has instructions for how to alert wikiprojects:

... You can then add {{WikiProject TOPIC}} at the top of the talk page.

• User will then go to the talk page, and taking an educated guess try to insert {{WikiProject Mathematics}}.
• For historical reasons this is not the banner for this project, instead it gives instructions to use {{maths rating}} or {{maths banner}} instead.
• The user will try to use the first inserting {{maths rating}}. This fails with instructions that the template {{maths banner}} should be used for drafts.
• Finally the user gets the right template which lists the article in the category.

This workflow is harder than it needs to be. At the least we can change {{WikiProject Mathematics}} to be clearer about which template to use. It might be possible to make it directly insert the right template.

The list and category are probably complementary. The list allows some sort of annotation and the category allows users to add list articles themselves. By adding the category to your watchlist you can keep track of new additions.--Salix alba (talk): 17:18, 5 July 2020 (UTC)

I have an opinion on the AfC process that I am not permitted to express due to a topic ban (by the way, many editors don't use AfC at all but just the draft space). Any case, yes, I agree that the list and category can be complementary and maintaining both is not a bad idea (just like we have "list of X" article as well as "glossary of X" article) -- Taku (talk) 23:49, 5 July 2020 (UTC)

The AfC and draft processes are intended as a way to let newbies think they are making articles but then keep the junk they create out of the real encyclopedia. Once that is understood, all other parts of the process that you might think to be backwards or wrong make sense. —David Eppstein (talk) 00:31, 6 July 2020 (UTC)

Afc ≠ draft space. Again, I'm not really allowed to respond to the comment like that. But, to stick to the facts, the *fact* is that this category has not been maintained in the past. There are many more facts I want to mention but I shouldn't (having this convention is too dangerous) -- Taku (talk) 00:51, 6 July 2020 (UTC)

The fact is that the list has also not been maintained in the past. When I checked yesterday (maybe it was fixed now) it included redirects from drafts that had been promoted to articles as long as three months earlier. —David Eppstein (talk) 01:33, 6 July 2020 (UTC)

It is *generally* well-maintained, I think.. Stopping the conversation. -- Taku (talk) 01:55, 6 July 2020 (UTC)

Draft:Peter Li

This draft needs work from an editor who is knowledgeable in mathematics. The subject probably satisfies academic notability, but the draft needs work. Robert McClenon (talk) 13:07, 4 July 2020 (UTC)

can i just move it by myself? IGNOREALLRULES? — Preceding unsigned comment added by Dennui (talk • contribs) 14:51, 4 July 2020 (UTC)

I'm very confused by the comment from your review "This draft does not establish academic notability as submitted. The subject probably is notable, based on the unverified statement that he is a fellow of the American Academy of Arts and Sciences." as one of the references is directly to his member page at the AAAS, which includes his citation.

Also, for anyone editing now (I'm too confused about the "new article" process to do it myself), there shouldn't be a comma between "differential" and "Harnack" Gumshoe2 (talk) 15:44, 4 July 2020 (UTC)

Amacad is definitely enough for academic notability and the draft looks adequate as a stub. —David Eppstein (talk) 16:30, 4 July 2020 (UTC)

Thank you. The draft was not in good shape, and the article looks satisfactory now. Robert McClenon (talk) 19:29, 4 July 2020 (UTC)

For some reason the title of the page has been changed from "Peter Li" to "Peter Wai-Kwong Li". I think this isn't appropriate since he is professionally known as Peter Li, and his name is given as such in virtually all (80 out of 81) of his papers. I can't understand how to modify the title, can someone help? Gumshoe2 (talk) 04:40, 6 July 2020 (UTC)

Done. Dennui (talk) 05:10, 6 July 2020 (UTC)

Talk:List of OEIS sequences#Requested move 4 July 2020

This discussion about a possible page move is perhaps of interest to the community here. XOR'easter (talk) 17:31, 7 July 2020 (UTC)

Talk:Cognitive-Theoretic Model of the Universe

A discussion has begun at Talk:Cognitive-Theoretic Model of the Universe which may be of interest to the community here. XOR'easter (talk) 05:25, 8 July 2020 (UTC)

There is a specifc RfC on the topic here: Talk:Cognitive-Theoretic Model of the Universe#Request for comment: on the notability of the CTMU in 2020 with sources published after 2006 and "unredirect" of this page to Christopher Langan - Scarpy (talk) 06:48, 8 July 2020 (UTC)

Daniele Catanzaro notable?

Is the topic in Daniele Catanzaro a notable one? The main contributor appears to have a COI, so I'm starting from that direction. --Izno (talk) 11:35, 10 July 2020 (UTC)

His citation level looks way low for WP:NPROF C1, and I don't see other evidence of notability. Looks like a good candidate for AfD. Russ Woodroofe (talk) 12:29, 10 July 2020 (UTC)

Minimum_evolution and Maximum parsimony (phylogenetics) may also need review as well. The latter already existed but he has now contributed heavily to that article; the former is entirely created by him. --Izno (talk) 13:31, 10 July 2020 (UTC)

As far as the article explains, he is a professor at a research university, with an active research program, as all such professors have. No other evidence of notability is given. Therefore he fails the average professor test. Mgnbar (talk) 13:34, 10 July 2020 (UTC)

Article in need of equation formatting

Surface_plasmon_resonance_microscopy has a number of equations written with custom formatting. I'm not to familiar with math formatting on-wiki. Could someone fro mthis project take a quick skim through to see if they're easily re-writable? Thanks in advance for any assistance! T.Shafee(Evo&Evo)^talk 01:29, 20 June 2020 (UTC)

@Evolution and evolvability: You weren't kidding! Michael Hardy made some improvements, I did some more, and there's still plenty to be done. I should note that some of the formulas whose formatting I improved are clearly either wrong or incoherent or both. --JBL (talk) 19:17, 25 June 2020 (UTC)

@JBL,Michael Hardy: Thanks! And also useful (and worrying) to know that they had errors/ambiguities. I've also pinged WP:phys on this, since fixing them is pushing my outside my abilities. T.Shafee(Evo&Evo)^talk 08:02, 27 June 2020 (UTC)

@Evolution and evolvability: Ok, sounds good. To be precise, it's clear that the numbered equation Eq. 9 cannot be what was intended. --JBL (talk) 13:51, 27 June 2020 (UTC)

As with any other content, apply WP:V. If there is doubt about an equation and it cannot be verified by reference to a cited source, delete it.--Srleffler (talk) 17:26, 27 June 2020 (UTC)

This is an absurd suggestion; the article has all sorts of problems, but people with no understanding of the content randomly deleting portions of it will make those problems worse, not better. --JBL (talk) 19:11, 27 June 2020 (UTC)

Yes, if you do not know the subject, but are sure the equation is wrong, then go to the source to find a correct version. If there is no source, then apply the citation needed template which will warn people that the equation should not be trusted. Just deleting it may make it difficult for someone who knows the subject to fix the article since it leaves him/her with no hint as to what was intended. JRSpriggs (talk) 08:44, 28 June 2020 (UTC)

I just did the remaining 2, I think that's all of them. There were outright mistakes in notation in these ones too, with things suddenly changing from line to line. But I have 0 background whatsoever in the topic and much of the text is incoherent so I found that all I could really do is format :( - Astrophobe (talk) 17:34, 27 June 2020 (UTC)

@Joel B. Lewis, Michael Hardy, JRSpriggs, and Astrophobe: To check in on this one, Charles Campbell (who does some research in this area) has offered to take a look through but asked if there are any that are still flagged as questionable? Thanks again for the assistance on this. T.Shafee(Evo&Evo)^talk 09:41, 11 July 2020 (UTC)

That's great! The ones that I worked on, Equations 13 and 14, remain (to my eyes) incoherent. The description of the variables under equation 13 makes no sense (I can't even parse the English), and among other things I have no clue what the dots mean in equation 14. Would be great to have an expert look at those. - Astrophobe (talk) 18:36, 11 July 2020 (UTC)

I've now asked specifically about Eqn 13 and 14. In the meantime, their previous feedback: "If you ask me, there are way too many equations. #1-11 are useless and should just be in the section on Surface plasmon resonance (SPR), and only referred to here in the SPRM section. I am sad to say the SPR section (which needs those equations) has essentially none. The important equations for SPRM are given in Eq. 1 and 49. The important equations for normal SPR sensing are given in my older attached paper. These equations have all stood the test of peer review and high citations." T.Shafee(Evo&Evo)^talk 12:19, 15 July 2020 (UTC)

References

Draft:Peano surface

This article may need some work. But it's useful. Dennui (talk) 09:28, 6 July 2020 (UTC)

Maybe potential to DYK. Dennui (talk) 09:28, 6 July 2020 (UTC)

Thanks a lot to everyone who is helping to improve the article! Dennui (talk) 09:22, 9 July 2020 (UTC)

Striking out sock contributions. It doesn't even seem like passing notability; let alone be long enough for DYK. Eumat114 (Message) 05:51, 14 July 2020 (UTC)

Thanks for the sockstrike, but it looks notable enough for an article to me. And it's well over minimum length for DYK. But it's not yet in shape to promote to article space. —David Eppstein (talk) 07:20, 14 July 2020 (UTC)

Thanks. I'm not well versed in mathematics history, so...thanks for the cleanup. But is it "interesting" enough for a DYK (its interest seems to be quite technical...why am I even asking this when the draft is not in mainspace yet?) Facepalm Eumat114 (Message) 07:23, 14 July 2020 (UTC)

I'm less sure about that. I tend to nominate new mathematics articles for DYK only when there is some chance that they or at least their hook can have some wider appeal, and I don't see it yet for this one. —David Eppstein (talk) 07:35, 14 July 2020 (UTC)

Now an article (again): Peano surface. I have no particular intention of taking it to DYK but if someone else wants to I won't object. —David Eppstein (talk) 04:46, 16 July 2020 (UTC)

SpringerEOM move

The Encyclopedia of Mathematics has moved recently and is now no longer under Springer but EMS. This is causing a problem in that it looks like all (or most, at any rate) of the links generated by Template:SpringerEOM are now broken. See Template talk:SpringerEOM#It looks as though EOM has left Springer for more details. The template is used an large number of articles, so it's unclear how big of a problem this will turn out to be. --RDBury (talk) 01:08, 16 July 2020 (UTC)

I've changed the template to use the |title= rather than the |id= parameter this should fix most, but not all links. --Salix alba (talk): 11:59, 16 July 2020 (UTC)

Create redirect

Hi,

Can someone create redirects to Homotopy Lie algebra and Homotopy associative algebra from pages titled "$L_{\infty }$-algebras" and "$A_{\infty }$-algebras", respectively? Most people don't call these objects Homotopy X algebras and instead use the shorthand version. I'm not sure how to do this. Wundzer (talk) 03:04, 16 July 2020 (UTC)

I created L-infinity algebra and A-infinity algebra as redirects. I'm not sure how one one would type $L_{\infty }$ in the search box, but the spelled-out versions are clear enough and used in places like nLab. --{{u|Mark viking}} {Talk} 03:30, 16 July 2020 (UTC)

Ah, thank you! For your question, I know the A-infinity operad uses an ∞ in the title on the page, but when you search for it, they use your format. I think the big thing I care about is being able to type in "A infinity algebra" into a browser and get the correct wiki page. Wundzer (talk) 01:19, 17 July 2020 (UTC)

Use the symbol of pi

Despite π is more commonly used, please do my request: Move the page Six nines in pi to Six nines in π over redirect. 78.190.25.41 (talk) 15:40, 17 July 2020 (UTC)

You can use the WP:Move request process on the talk page of the article in question if you believe the title should change. --Izno (talk) 16:05, 17 July 2020 (UTC)

Markov chain split

Feedback is welcome at Talk:Markov chain#Potential split. In addressing the {{Very long}} template on Markov chain that's been there since February 2017, I believe we need a split and articles with clear focuses on DTMCs, CTMCs or Markovity. — Bilorv (talk) 23:16, 20 July 2020 (UTC)

Sourcing of Numerical digit

I'm working on improving the sourcing of Numerical digit. there's a lot of interesting history in that article that was largely unsourced. While I found some sources and finding some claims that I'm struggling to find sourcing for. I dropped a note on the article talk page, indicating may interest in looking for sourcing and asking for help, but I noticed and the first person to post on that talk page in eight years, so I'm posting this here to get a few more eyes on it.

My intention is to remove material that cannot be sourced.--S Philbrick(Talk) 13:20, 23 July 2020 (UTC)

Sector/fanning?

I've just removed a link from the Fanning disambiguation page to Sector (disambiguation)#Geometry because I didn't understand how that topic is related to "fanning", and couldn't find it explained at any of the targets. If anyone watching this project knows what the connection is and can add it back with a brief explanation, that would be most helpful. Ivanvector (^Talk/_Edits) 21:27, 23 July 2020 (UTC)

Something to do with Polyhedral complex#Fans maybe? —David Eppstein (talk) 22:11, 23 July 2020 (UTC)

There is also the concept of fanning curves in Grassmannian manifolds, e.g., [12]. Perhaps a more simplistic explanation is that a circular sector looks like the profile of a hand fan. --{{u|Mark viking}} {Talk} 22:45, 23 July 2020 (UTC)

Thoughts and idea

Hello, Any new thoughts on an old topic of discussion on WP:NACADEMIC notability? Discussion here: https://en.wikipedia.org/wiki/Wikipedia_talk:Notability_(academics). Cheers Earthianyogi (talk) 08:49, 26 July 2020 (UTC)

Draft review request

Hello, an Articles for Creation reviewer here. I have read over my friend's draft of the Lifting the Exponent lemma, but because 1. I have little to no experience reviewing math articles and 2. I feel like there would be a conflict of interest if I accept an article written by my friend, I was wondering whether there were any AfC reviewers in WikiProject Math who are willing to take a look. I myself have looked over it, and in my opinion, it seems understandable and well-written, especially since this is my friend's first Wikipedia article. Thanks, GeneralPoxter (talk) 19:25, 16 July 2020 (UTC)

Looks like a good start, at the very least! A few quick thoughts: first, within the last few decades sounds vague (more than 10 and less than 50? 70? years). Perhaps a phrasing like since the early 2000s would work better. Second, postings on the arXiv are not peer-reviewed and so are not considered reliable sources, except in unusual circumstances. It looks like there is a peer-reviewed paper, Heuberger and Mazzoli (2017), that could be cited but currently isn't. Cheers, XOR'easter (talk) 22:45, 16 July 2020 (UTC)

Although the "lifting the exponent" name for this result may well be modern, essentially that result goes back at least as far as Gauss (see Disquisitiones Arithmeticae, article 87). Joseph Myers (talk) 23:44, 16 July 2020 (UTC)

Thank you for all of your suggestions. I have added the new details into the article. cstryn (talk) 15:25, 26 July 2020 (UTC)

Good Article nomination for Pell's equation

Pell's equation has been nominated for Good Article status. Although recent edits to the article and its nomination should be credited to Eumat114, I think I'm too involved (by contributing most of the solutions section in 2010 and the lead image in 2012) to review it myself. But if someone else here is willing to, that would be helpful. See Wikipedia:Good article nominations#Mathematics for the nomination (and the top of the same page for pointers to reviewing guides). —David Eppstein (talk) 19:45, 21 July 2020 (UTC)

The "Transformations" section seems to be written more textbook-style than the rest, and it's sourced to somebody's Google Sites page. Other than that, I didn't see any major issues on a first reading. I hope to go through it more carefully soon. XOR'easter (talk) 21:17, 21 July 2020 (UTC)

FYI, I am currently on a project about Pell's equation and hence will have access to more sources. I'll sort that section out soon enough. Eumat114 (Message) 05:01, 22 July 2020 (UTC)

Great! XOR'easter (talk) 06:45, 22 July 2020 (UTC)

Should there be a section on the role of Pell's equation in some proofs of Matiyasevich's theorem, which laid Hilbert's 10th problem to rest? Michael Hardy (talk) 19:39, 26 July 2020 (UTC)

Relatedly, why are the applications to Størmer's theorem and Archimedes' cattle problem tagged onto the end of a section on connections to continued fractions? —David Eppstein (talk) 19:55, 26 July 2020 (UTC)

I made the bit about Størmer's theorem into its own subsection and trimmed that mention of Archimedes' cattle problem, since the text mentions it twice before then. XOR'easter (talk) 21:32, 26 July 2020 (UTC)

I ran through a source check on the "Transformation" part. It appears that a large chunk of it is original research, and only a small part of it can be remotely related to sources. Some of the statements are worth keeping, under the "Generalized Pell's equation" section; however, much of it seems to be OR conducted by one (or more) mathematicians and is not worthy of inclusion. Eumat114 (Message) 14:36, 27 July 2020 (UTC)

So I'm gonna be WP:BOLD and remove the entire OR section while trying to source valuable content. Eumat114 (Message) 14:38, 27 July 2020 (UTC)

FWIW, that section seems to have been added by Titus III back in 2009. They still appear to be an active editor, perhaps they could weigh in on whether this is their own research or whether there are sources for it. --JBL (talk) 14:54, 27 July 2020 (UTC)

Joel B. Lewis, I know it is not exactly OR but rather, the user sourced the content to what looks like somebody else’s OR. Good idea to ask. Eumat114 (Message) 01:26, 28 July 2020 (UTC)

Aug 2020

Simpson correspondence

An editor suggests to rename the article Simpson correspondence to, e.g., "Simpson-Corlette correspondence", arguing that the current name does not properly reflect the contributions of Corlette on that topic. I am a bit unsure how to proceed: from what I can tell, this name is not used in the literature, despite the fact that Corlette's contributions are (as is also clear from the literature) very clearly noteworthy to that topic. What are the relevant guidelines for naming mathematical topics after their contributors etc.? Jakob.scholbach (talk) 09:13, 29 July 2020 (UTC)

This probably falls under WP:COMMONNAME, which advises to use the most common name for a topic. "Simpson correspondence' gets 401 hits on GScholar and "Simpson-Corlette correspondence" gets only two links, to the same thesis. WP:RIGHTGREATWRONGS is also relevant. --{{u|Mark viking}} {Talk} 09:41, 29 July 2020 (UTC)

Actually, in my opinion, the page should be renamed to Non-Abelian Hodge theorem or Non-Abelian Hodge correspondence, which is the generally accepted term in the mathematical community for this correspondence (Simpson correspondence is also frequently used of course). Based on Google scholar results if you include the variations (non-abelian, non abelian, theorem/theory) you get more results than Simpson correspondence (and even with just "non abelian hodge theory" produces 500 results). This is both a more evocative name for the correspondence, (slightly) more universally recognized, and avoids the issue of discussing who deserves more credit in the title (to be clear, both Simpson and Corlette made significant contributions to the final result, although the key arguments were really completed by Simpson, but such a summary of the contributions could be added to the article). I had planned on expanding this article myself in the near future, and will probably request a move to Non-Abelian Hodge theorem regardless of whether it gets renamed in the meantime. Tazerenix (talk) 10:26, 29 July 2020 (UTC)

OK, thanks -- this strikes me as a good solution, so I have moved the article to Nonabelian Hodge correspondence. Jakob.scholbach (talk) 08:58, 30 July 2020 (UTC)

After the move I have filled the page out with a long introduction to the theorem and a history of who proved what. This should completely resolve the problem. Tazerenix (talk) 11:24, 4 August 2020 (UTC)

Differential geometry of surfaces

Can someone have a look on this article and its talk page, where an edit war is starting about whether the section Differential geometry of surfaces#Function theory in two variables must be removed as out of scope, or must be kept. Thanks in advance. D.Lazard (talk) 20:35, 3 August 2020 (UTC)

@D.Lazard: I took a look and gave my thoughts. Let me know if the dispute develops further. — MarkH₂₁^talk 21:20, 3 August 2020 (UTC)

I also gave my thoughts. Tazerenix (talk) 00:27, 4 August 2020 (UTC)

Thanks for the help. The edit war continue. I have reach 3 reverts (even if it is unclear which edit should be counted as the first revert). So, your help is still needed. D.Lazard (talk) 13:11, 5 August 2020 (UTC)

Approximately vandal

Just a heads-up to all: about a year ago, there was a fairly disruptive vandal that had a habit of inserting statements like 3×3 approximately equals 9 (among other equally inane things). The original ANI thread is here, which led to a rangeblock due to rotating IPs. That range is currently blocked again, but I don't know if that's related or not. In any case, Special:Contributions/81.151.174.89 appears to be the same person back at it. They only got 4 edits in before being blocked by Materialscientist, but it's a short block, and if they're able to rotate IPs again, it might be worth keeping your eyes open for more of similar nonsense. –Deacon Vorbis (carbon • videos) 15:29, 5 August 2020 (UTC)

That is such a bizarre form of vandalism to be so persistent with! — MarkH₂₁^talk 19:36, 5 August 2020 (UTC)

Everybody needs a hobby, I guess.... XOR'easter (talk) 00:02, 6 August 2020 (UTC)

Links to "Fast Fourier Transform" that ought to link instead to fast Fourier transform

There are lots of links to Fast Fourier Transform that ought to link instead to fast Fourier transform. I've recently fixed a bunch of them. Can others help?

A subtler thing occurs when someone writes "For this purpose we use the Fast Fourier transform." where they ought to write instead "For this purpose we use the fast Fourier transform." This is subtler because when you click on "What links here", these are not distinguished from other links to the article's proper title, since the initial letter is not case-sensitive in links. (The psychologically contagious nature of capital letters is apparent from long experience with Wikipedia editing. Has anything been published about it?) Michael Hardy (talk) 00:07, 6 August 2020 (UTC)

Discussion about wikipedia "Wikipedia:Village pump (proposals)"

You are invited to join the discussion at Wikipedia:Village_pump (proposals)#Deprecate parenthetical citations, which is about a wikipedia that is within the scope of this WikiProject. – Finnusertop (talk ⋅ contribs) 06:21, 6 August 2020 (UTC)

Expert attention

This is a notice about Category: articles needing expert attention, which might be of interest to your WikiProject. It might take a while before the category is populated. There might be as few as one page in the category, or zero if someone has removed the expert request tag from the page. 2600:100E:B11E:43A3:DCBA:4FC5:7056:EF53 (talk) 14:42, 10 August 2020 (UTC)

Centroid

In the article titled Centroid, we find this:

The centroid of a non-self-intersecting closed polygon defined by n vertices (x₀,y₀), (x₁,y₁), ..., (x_n−1,y_n−1) is the point (C_x, C_y), where

$C_{\mathrm {x} }={\frac {1}{6A}}\sum _{i=0}^{n-1}(x_{i}+x_{i+1})(x_{i}\ y_{i+1}-x_{i+1}\ y_{i}),$ and

$C_{\mathrm {y} }={\frac {1}{6A}}\sum _{i=0}^{n-1}(y_{i}+y_{i+1})(x_{i}\ y_{i+1}-x_{i+1}\ y_{i}),$

and where A is the polygon's signed area, as described by the shoelace formula:

$A={\frac {1}{2}}\sum _{i=0}^{n-1}(x_{i}\ y_{i+1}-x_{i+1}\ y_{i}).$

In these formulae, the vertices are assumed to be numbered in order of their occurrence along the polygon's perimeter; furthermore, the vertex ( x_n, y_n ) is assumed to be the same as ( x₀, y₀ ), meaning $i+1$ on the last case must loop around to $i=0$. (If the points are numbered in clockwise order, the area A, computed as above, will be negative; however, the centroid coordinates will be correct even in this case.)

References

• Bourke, Paul (July 1997). "Calculating the area and centroid of a polygon".

Did I clumsily miss something, or should the second formula be as follows?

$C_{\mathrm {y} }={\frac {1}{6A}}\sum _{i=0}^{n-1}(y_{i}+y_{i+1})(y_{i}\ x_{i+1}-y_{i+1}\ x_{i})$

Michael Hardy (talk) 22:23, 5 August 2020 (UTC)

Think the second product factor in $C_{y}$ just has to match what is in $A$. Deriving the formulas probably yield what you suggested, but with a negative $A$, and cancelling the negatives give the original formulas, and save us from defining $A_{x},A_{y}$. I'm just guessing, though. Walwal20 ^{talk ▾ contribs} 22:59, 5 August 2020 (UTC)

(ec) @Michael Hardy: To calculate the centroid we decompose the figure into oriented triangles between points $O$, $P_{i}$ and $P_{i+1}$. The centroid of the $i$-th triangle is ${\frac {O+P_{i}+P_{i+1}}{3}}$, hence the term $0+x_{i}+x_{i+1}$ for $C_{x}$ and similar for $C_{y}$. The weight of the triangle's centroid in the sum is the triangle's area (signed!) which is a half of the cross-product of the $i$-th and $(i+1)$-st vectors - hence the same second paren both for x-es and y-s. The common factors 1/3 and 1/2 are moved outside the sum and make the 1/6 there.

If you swap the terms in the second parenthese, you'll effectively change the paren's sign and get a negated value for $C_{y}$ as a result. --CiaPan (talk) 23:07, 5 August 2020 (UTC), edited 07:11, 6 August 2020 (UTC) and 10:59, 6 August 2020 (UTC)

@Michael Hardy: You might just test it yourself: take a triangle with vertices (0,0), (0,1) and (1,0) and calculate its centroid. There will be just one non-zero term in each of there sums, and the hardest part of calculation will be a division (1/6):(1/2).
:) CiaPan (talk) 12:49, 6 August 2020 (UTC)

@CiaPan: and @Walwal: : Thank you for your attention to this. Michael Hardy (talk) 21:10, 10 August 2020 (UTC)

Abstract cell complex

• Abstract cell complex (edit | talk | history | protect | delete | links | watch | logs | views)

I just saw this article, the vast majority of which was written (with some broken English) by a single user who appears to be the author of a book/application that the article is serving as a bit of a coatrack for. As far as I can tell, the basic topic is probably at least borderline notable enough for a separate article (the Klette article cited has a description and some further references), but the digression into the research of Kovalevsky is probably too much. But I'd certainly welcome a second opinion on this one. Thanks, –Deacon Vorbis (carbon • videos) 14:09, 11 August 2020 (UTC)

Technical issues with Chrome rendering formulas

If anyone has experienced blurry math formulas in Chrome recently, you may be interested in a thread I've just started: Wikipedia:Village pump (technical)#Change to Chrome rendering of PNGs causing blurry formulas. –Deacon Vorbis (carbon • videos) 17:36, 12 August 2020 (UTC)

Expert attention on Differential Geometry of Surfaces

I would appreciate some experts on differential geometry to weigh in over here. Mathsci (talk · contribs) and I have both been editing the wiki page in the last few days. I find many of his edits to be written confusingly; according to my understanding of the material, his comments on the talk page do not address my complaints. Conversely he seems to think I am making too many major edits to his material. I have no interest in an argument and would like to defer to community consensus one way or another, but for the moment it's just me and him. Gumshoe2 (talk) 22:28, 10 August 2020 (UTC)

A lot of this article was edited by me in 2008. In the past I have edited a lot of mathematical content on wikipedia, starting in 2006. The concern with the current article has been to patch missing sections at the beginning of the article. That involved adding definitions from standard textbooks. Later, lecture notes of Nigel Hitchin suggested that it might be a good idea to have some material on covariant derivatives. I started by editing using Hitchin's notes and then Boothby's book on differential geometry. While editing, I had included Brioschi's proof of Gauss' Theorema Egregium (from Dirk Struik's book). Gumshoe2 then moved the material I edited on Brioschi's proof to another section. He also completely rewrote the section on covariant derivatives. From my point of view it is currently not properly sourced. That could probably be remedied using Thorpe's book on Elementary topics in differential geometry. The standard sources for this material are Helgason's book on Differential Geometry and do Carmo's book on Riemannian geometry. I like that material, but it is probably at the level of graduate students.

However, the aim in this article has always for it to be accessible to a wide readership. So covariant derivatives are probably out of the scope of the article, unless carefully presented (finding the sources).

I have twice given courses on the Atiyah-Singer index theorem in the UK: part of that required the theory of Riemannian covariant derivatives. It's on public record that I have had a stroke, which has had some consequences. Mathsci (talk) 23:35, 10 August 2020 (UTC)

I you have health problems that have no consequence on your work as Wikipedian, this is not worth to mentioning them. It they have consequences, it is to you to decide whether they allow you to conveniently edit Wikipedia, and if they not, to decide to stop editing Wikipedia. So, in any cases, it is not worth to mention here your health problems. D.Lazard (talk) 09:29, 11 August 2020 (UTC)

By the way, Mathsci has opened a WP:ANI discussion, entitled "D.Lazard and Differential geometry of surfaces", in which it is discussed whether WP:BOOMERANG must apply. D.Lazard (talk) 09:29, 11 August 2020 (UTC)

The usual five pillar always apply: articles require WP:RS when creating content. I am currently reading John A. Thorpe's book, "Elementary topics on differential geometry." I looked at your editing history. The article system of polynomial equations was created by you in 2010. That content described your own research. Mathsci (talk) 11:48, 11 August 2020 (UTC)

In my mind, each of the sentences in the previous post by Mathsci contains pretty much no relevant information to the discussion at hand. @Mathsci: if there is an issue here, it would be helpful to precisely (and concisely) state what is going on and refrain from adding unrelated bits of information. Jakob.scholbach (talk) 07:14, 12 August 2020 (UTC)

No problem. For smooth surfaces $S$, the standard formalism requires (tangent) vector fields $X$ viewed as derivations of $C^{\infty }(S)$. The notion of affine connections is introduced through the covariant derivative $\nabla _{X}$ which yields a vector field $\nabla _{X}Y$ from two vector fields $X$ and $Y$. The Riemannian connection of Levi-Civita is easy to construct directly using a projection operator, assuming an isometric embedding in Euclidean space. Its properties of compatibility with the metric and symmetry follow from the construction or can be proved directly as part of the fundamental theorem of Riemannian geometry. The curvature operator is defined as $R(X,Y)=[\nabla _{X},\nabla _{Y}]-\nabla _{[X,Y]}$. The assignment $(X,Y,Z,W)\mapsto (R(X,Y)Z,W)$ is $C^{\infty }(S)$-linear in all of its four variables. Elementary algebra shows that, if $v_{1}$ and $v_{2}$ are linear independent tangent vectors at a point in $S$, the quantity $(R(v_{1},v_{2})v_{2},v_{1}))/((v_{1},v_{1})(v_{2},v_{2})-(v_{1},v_{2})^{2})$ is independent of the choice of basis. It is the Gaussian curvature at that point. As a corollary, any local isometry of surfaces preserves Gaussian curvature.

This is standard material that generalizes to any even dimension; there are lots of sources (including Thorpe's book). The material can be presented in a coordinate-free way (as here), with Christoffel symbols (classical) or both (perhaps the best option). Mathsci (talk) 09:06, 12 August 2020 (UTC)

I fail to see how any of this (in the post right above) relates to an alleged misbehavior of D.Lazard. Jakob.scholbach (talk) 09:21, 12 August 2020 (UTC)

The question for the noticeboard was not about D.Lazard. It was about the section in the article on covariant derivatives. My post above yours specifically addressed that topic. The area of the article has always been studied by undergraduates. The aim of the article was to present the material for a general readership. The first diff of Gumshoe2 was about a technical detail with covariant derivatives, which can be resolved (using my previous post, specialized to the material of Hitchin, Thorpe et al). Where there might be a disagreement is with inline citations: for a general readership it seems they really have to be supplied. Mathsci (talk) 10:49, 12 August 2020 (UTC)

This is a notice that I started Draft:Calculus on Euclidean space. As I see, there are two issues: (1) how to cover calculus topics in some systematic and centralized manners as opposed to having separate articles and (2) how much background materials should be in differential geometry of surfaces. I am with Mathsci that the issue (1) is indeed an issue; thus, I have started that draft page by copying the section on functions in 2 variables. Mathsci has said above: "This is standard material that generalizes to any even dimension." I want to believe that draft page (eventually a mainspace article) can cover such standard materials. As for (2), I don't have much opinion other than one I made at the talkpage of the diff-geo article. -- Taku (talk) 00:11, 17 August 2020 (UTC)

I need to mention that there is Draft:Analysis of vector-valued curves, which has a section closely related and thus I am thinking of moving that section to Draft:Calculus on Euclidean space. -- Taku (talk) 00:52, 17 August 2020 (UTC)

Taku, thans for your replies. I agree with you about the topics you've raised. As far as calculus on Euclidean space is concerned, I think everything generalises to any dimension. Hörmander takes a little care about C^k issues. On the talk page of your calculus draft, I have mentioned that mixing elementary material on calculus with more advanced material, such as differential topology (smooth manifolds, differential forms, etc) seems unrealistic. Calculus is quite elementary. Understanding differential forms, orientablity, etc, is more advanced. Also for smooth surfaces, there's no need to invoke the general theory of manifolds, submanifolds, Stokes's theorem, etc. Mathsci (talk) 13:44, 17 August 2020 (UTC)

The disagreement over two-dimensional calculus was an independent problem some people had with Mathsci at the Differential geometry of surfaces page, not related to this one. I've made a comment on the talk page to your draft Gumshoe2 (talk) 09:29, 17 August 2020 (UTC)

Yes, but I do believe Mathsci has a valid point that some background stuff seems missing or not well-organized in a single place in Wikipedia, that is needed to read differential geometry of surfaces. He often refers to materials in existing literature, and, since Wikipedia is supposed to be *a summary of established math*, we do indeed need to have some presentation of those materials. The question is "how" not "if" (the draft like this one I started should be one approach). I will be responding to points specific to the draft in the talkpage of the draft. -- Taku (talk) 03:57, 18 August 2020 (UTC)

Has Kunen died?

An IP editor has been editing Kenneth Kunen as though he has died. Is that true? I don't find any news story about it on a brief search. --Trovatore (talk) 18:53, 15 August 2020 (UTC)

I don't know but it's obviously not acceptable to put it into the article without a source, so I've reverted the IP. (I've also left a message on the IP's talk page asking if they have a source.) --JBL (talk) 19:11, 15 August 2020 (UTC)

I concur; I was about to revert it myself but you got there first. Thanks for taking care of it and for leaving a note at the IP's talk page. XOR'easter (talk) 19:43, 15 August 2020 (UTC)

Answer appears to be yes, sadly. Article now has a source for it. —David Eppstein (talk) 17:13, 18 August 2020 (UTC)

Expected mean squares

I have created an article titled Expected mean squares. I think the plural may be justified by the fact that nobody (as far as I know?) ever has occasion to think about just one expected mean square, in view of their use in forming F-tests. Michael Hardy (talk) 00:05, 20 August 2020 (UTC)

Administrators' noticeboard section on differential geometry

There is currently a discussion at Wikipedia:Administrators' noticeboard regarding an issue with Mathsci (talk · contribs), Gumshoe2 (talk · contribs), D.Lazard (talk · contribs) and the articles on Symmetry of second derivatives, Differential geometry of surfaces. At the moment I'd like this to focus more on a possible process to follow rather than the actual dispute. --Salix alba (talk): 16:03, 22 August 2020 (UTC)

Page deletion - Mirror symmetry conjecture

Hi,

I migrated the material on Mirror symmetry conjecture to Mirror symmetry (mathematics). Will someone remove the first article since the second's title is more in line with wikipedia standards? Here's the analogy: Mirror symmetry is to Mirror symmetry (mathematics as Gauge theory is to Gauge theory (mathematics). Wundzer (talk) 16:35, 18 August 2020 (UTC)

Unfortunately, by simply moving the content over, you have destroyed the edit history. The preferred way to make such a change is described at Wikipedia:Moving a page. You can do it yourself. :) Mgnbar (talk) 16:46, 18 August 2020 (UTC)

Actually, now that you've created Mirror symmetry (mathematics), you won't be able to move Mirror symmetry conjecture. You'll have to create a request at Wikipedia:Move requests. Mgnbar (talk) 16:51, 18 August 2020 (UTC)

What does it mean that the second title is "more in line with wikipedia standards"? Generally article titles on Wikipedia use parenthetical disambiguation when more natural disambiguation is not available. I have marked the new article for speedy deletion; after it is removed, we can start over with appropriate process, including perhaps a discussion of whether retitling is appropriate at all. --JBL (talk) 16:54, 18 August 2020 (UTC)

(edit conflict):It appear that you have copied the article instead of doing a move (see WP:MOVE). Moreover the title you suggest is definitively not in line with WP standards, in particular with WP:LEAST, as, for most mathematicians, "mirror symmetry" is synonymous with reflection symmetry. So, I'll redirect the new article, and its talk page to Reflection symmetry. If you want to change an article title, please follow the procedure described at WP:Move request. D.Lazard (talk) 16:58, 18 August 2020 (UTC)

I think that's largely incorrect. As far as professional mathematicians are concerned, mirror symmetry typically refers to the results from string theorists in the 90's and the related programs which came out of it. Here's a list of resources by professional mathematicians alive today who use Mirror symmetry to refer to this area: http://www.claymath.org/library/monographs/cmim01c.pdf , https://ncatlab.org/nlab/show/mirror+symmetry , https://mathoverflow.net/questions/tagged/mirror-symmetry , https://arxiv.org/search/advanced?advanced=&terms-0-operator=AND&terms-0-term=mirror+symmetry&terms-0-field=all&classification-mathematics=y&classification-physics=y&classification-physics_archives=math-ph&classification-include_cross_list=include&date-filter_by=all_dates&date-year=&date-from_date=&date-to_date=&date-date_type=submitted_date&abstracts=show&size=50&order=-announced_date_first Wundzer (talk) 17:17, 18 August 2020 (UTC)

How can I recover the edits I made on Mirror symmetry (mathematics)??? I'm very frustrated these changes were deleted: I want to put them on the Mirror symmetry conjecture page... Wundzer (talk) 17:11, 18 August 2020 (UTC)

Is this page about the same topic as Homological_mirror_symmetry??? --JBL (talk) 17:12, 18 August 2020 (UTC)

No! Homological mirror symmetry is a separate formulation of mirror symmetry. These are not interchangeable and mean different things. Wundzer (talk) 17:14, 18 August 2020 (UTC)

There's some discussion on the talk page about the topic and the expository approach. (It's not 100% clear to me that it warrants its own page, but I'm not an expert on the topic.) It'd be nice to have some more commenters. Gumshoe2 (talk) 17:26, 18 August 2020 (UTC)

Let me explain the reasoning: Mirror symmetry generally refers to the more analytic and combinatorial part of the subject. It studies things like Quantum cohomology, Gromov-witten invariants, and Picard-Fuchs differential equations. On the other hand, homological mirror symmetry is more focused on studying a (partly) conjectural equivalence of categories, the derived category of coherent sheaves and the Fukaya category. This area uses tools like A-infinity categories, Hochschild homology, and derived geometry. I think separating out the subjects is warranted, but the Homological mirror symmetry page is in serious need of a clean-up: it reads like a pop-science article but contains sparse content. This could be re-written to include some of the formulations and discuss some of the proofs, like HMS on the elliptic curve, Seidel's proof for K3 surfaces using Vanishing cycles, and Sheridan's article on HMS for hypersurfaces. Wundzer (talk) 17:52, 18 August 2020 (UTC)

Just be careful to make sure your content is as accessible as possible. I believe the ideal wiki article is quite different from an ideal review article. Gumshoe2 (talk) 18:12, 18 August 2020 (UTC)

I agree with making the material accessible and that's the main reason why I care about writing these articles. I think writing in the survey/review format is good for a baseline model because it is easy to expand upon and link to relevant material. Moreover, it organizes the material in a top-down fashion which (I think) can help make it a great wiki article. I do try my best to make content accessible, but will make sure to keep a keener eye for linking relevant material. Wundzer (talk) 20:03, 18 August 2020 (UTC)

Fixing page redirect

It seems like there is an edit war afoot with the Mirror symmetry (mathematics) link. I outlined above reasons why this should either be kept where it was, or directed to the Mirror symmetry conjecture page. But, here's an itemized list of these reasons

1. I think the general mathematics community should dictate the use of the terminology "mirror symmetry".
2. There are a few ways to measure this dictation: by looking at different resources mathematicians use and see how they use "mirror symmetry" and what subject it refers to.
3. Before continuing on to the list, note that the redirect is going to a small, basic idea, part of a single lecture or two on group theory, instead of a large wide-open field with many interesting problems that several prominent mathematicians have studied and are continuing to work on to this day.
4. A quick search on the arxiv shows that most papers being published refer to mirror symmetry in the sense of string theory
5. There are several books related to the study of mirror symmetry, including this Clay math monograph. You can look at [13] for the keyword "mirror symmetry" and find countless other books only discussing it in the sense of string theory.
6. Mathoverflow uses the mirror-symmetry tag to refer to questions related to the mathematical physics topic.

Moral of the story, I think having this redirect toward Reflection symmetry is myopic at best, and petty at worst. Wundzer (talk) 20:01, 19 August 2020 (UTC)

Without weighing in on the merits here, it is at least clear that the actions D.Lazard has put in motion are in poor form. For example, it's plainly indefensible to have requested this move as an "uncontested technical request" after it was clear that Wundzer would object. --JBL (talk) 22:15, 19 August 2020 (UTC)

Also pinging @Anthony Appleyard:, who actually carried out the move. (The current status is that Mirror symmetry and Mirror symmetry (disambiguation) are both disambiguation pages, which is obviously ridiculous.) --JBL (talk) 22:18, 19 August 2020 (UTC)

Hi, thanks for your response. I thought the original disambiguation page was put into oblivion and basically rewrote it into the Mirror symmetry page. This is because many of the redirects at the top of wiki pages used the Mirror symmetry redirect. Wundzer (talk) 22:27, 19 August 2020 (UTC)

I've reverted Mirror symmetry (mathematics) back to redirecting to the dab page Mirror symmetry, this would allow any user to find the page they are looking for, being either the Mirror symmetry conjecture or the far more common usage of it being used as a synonym of Reflection symmetry. I think the principle of least astonishment WP:R#ASTONISH holds here. A user expecting to find the common usage would be highly astonished to arrive at a string theory article. --Salix alba (talk): 22:23, 19 August 2020 (UTC)

I'm not convinced this is a common usage of the term "mirror symmetry". Do you have any common references for where this is used? It is the first time I've run across this terminology. If it is the case that I'm ignorant about this usage, then I think this is the correct course of action, otherwise I think it's unwarranted Wundzer (talk) 22:27, 19 August 2020 (UTC)

When I throw the words "mirror symmetry" into my favorite search engine (in private browsing mode), I get approximately equal numbers of hits for the elementary geometric meaning and for the string theory-related meaning on the first few pages of results. When I use my second-favorite search engine, I get about 4-to-1 hits for the string theory meaning versus the elementary meaning. When I use my third-favorite search engine, I get about 3-to-1 hits for the elementary meaning versus the string theory meaning. To me, this suggests there's no primary topic. I would propose restoring the situation as it was before D.Lazard's latest actions: Mirror symmetry a disambiguation page, with Mirror symmetry (mathematics) pointing towards it, and no such page as Mirror symmetry (disambiguation). --JBL (talk) 22:49, 19 August 2020 (UTC)

JBL, unilateral/bold page moves which are contested after the fact (in some reasonable time proximity) may be reversed using the technical queue. (Think of it as the revert in BRD.) They then can be submitted to the full move request process. See WP:RMUM. --Izno (talk) 22:46, 19 August 2020 (UTC)

Thanks, Izno. Because many things are going on simultaneously, it may be best in this case to reach consensus before patching everything back up again. --JBL (talk) 22:49, 19 August 2020 (UTC)

Some alternative redirect names

• Mirror symmetry (mathematics) -> Mirror symmetry conjecture
• Mirror symmetry (algebraic geometry) -> Mirror symmetry conjecture
• Mirror symmetry (group theory) -> Reflection symmetry

Here's my running opinion: since search engine results give some ambiguity, I think Mirror symmetry (mathematics) should direct to the disambiguation page. This disambiguation page should have a subsection for uses in mathematics and a subsection for other uses. Then, create redirection pages Mirror symmetry (algebraic geometry) -> Mirror symmetry conjecture and Mirror symmetry (group theory) -> Reflection symmetry. Wundzer (talk) 00:04, 20 August 2020 (UTC)

Deciding whether there is a primary topic

I agree that I was bold by considering that the equality of an object with its mirror image was the primary meaning of "mirror symmetry", and adapting Wikipedia accordingly. Nevertheless, if there is a consensus on this primary meaning, my edits and the move are fully in accordance with MOS:DAB and must be restored. Otherwise, it is the previous state that must be restored.

The only argument that is given above against a primary topic is the number of hits given by research engines. IMO, this argument is biased for the following reasons. Until circa 1990, "mirror symmetry" was a synonymous of "reflection symmetry", that was often preferred by non-mathematicians as more intuitive. This can be seen by limiting the Scholar Google search to the period before 1990. Since this date, there is a tremendous research activity around the extension of this topic to theoretical physics and algebraic geometry. This explains why the new meaning of the term is predominant when a preference is given to recent articles. So, the number of hits given by research engines is not very significant for deciding a primary topic.

Another criterion for deciding a primary topic is historical establishment. This is in favour of the etymological meaning, as it is established for centuries, and the new meaning is derived from it.

IMO, the main criterion here is WP:LEAST: One may espect that most readers (that is all readers except theoretical physicists and algebraic-geometers) are looking for reflection symmetry, and will be confused to have to click twice and to choose between links that are esoteric for them, before finding the desired article.

By the way, as all the targets of these links are mathematical articles, Mirror symmetry (mathematics) and Mirror symmetry must have the same target, whichever it is.

Please, discuss here whether the older meaning is a primary topic, and wait for a consensus before further changes. D.Lazard (talk) 10:03, 20 August 2020 (UTC)

"Mirror symmetry" is the same as "Mirror symmetry (mathematics)" — there's a joke in there, somewhere, but I can't quite find it. Oh well. It's probably not a very good joke. --Trovatore (talk) 17:21, 20 August 2020 (UTC)

For myself, and I think for essentially all mathematicians I personally know, the phrase "mirror symmetry" has taken on a definitive meaning which refers to the string theory topic and to the corresponding mathematical conjectures and results. I just mean that as an observation, the limitations of which speak for themselves... Gumshoe2 (talk) 17:53, 20 August 2020 (UTC)

I think that is correct. Looking at all references to "Mirror symmetry" on Mathematical Reviews ("anywhere" on mathscinet), there are 2429 listings, most of which relate to the 1990 sting theory discoveries of Aspinwall, Candelas, Greene, Vafa, Witten, Yau, et al. The same is probably true for Paul Ginsparg's "arXiv". The SMF-AMS book on Mirror Symmetry by Claire Voisin is a reasonable reference. Mathsci (talk) 21:41, 20 August 2020 (UTC)

When should there be a decision about whether consensus is reached? Wundzer (talk) 22:41, 24 August 2020 (UTC)

Comment: Within the mathematical community Mirror symmetry always refers to the the algebraic geometry notion. I don't think there are any mathematicians who would use the word mirror symmetry to refer to basic reflection symmetry ideas (partly because the name has been well and truly co-opted by algebraic geometry, and partly because no one studies that kind of thing anymore). I disagree with Mirror symmetry going directly to the reflection symmetry page, but I also think it's probably better to have a DAG page instead of going straight to the mirror symmetry conjecture. If I had to pick I'd say make it the MSC page, as this more accurately reflects what mainstream mathematics views the term to mean.Tazerenix (talk) 23:23, 24 August 2020 (UTC)

This sort of no true Scotsman snobbiness, defining the mathematical community as only being the people that study the topics that the in-group of research mathematicians have deemed to be important research, and disavowing the mathematics done even as academic research by anyone else, is exactly the sort of thing Branko Grünbaum decried over 40 years ago in his lectures on lost mathematics. Meanwhile, in the broader mathematical community, including people who prove theorems in academic research but not as members of pure mathematics departments, people who teach mathematics to schoolchildren, people who write textbooks for those teachers, or people who read or write Wikipedia articles on mathematical topics, "mirror symmetry" remains more likely to be understood as a synonym for reflection symmetry than as a specialized topic in advanced theoretical physics. One can find many current research articles, if not in what you would think of as real mathematics, that use "mirror symmetry" in its colloquial sense: see, e.g. approximately 640 papers since 2016 in Google scholar that use the exact phrase "mirror symmetry" in connection with bilateral symmetry, in fields including cognitive psychology, computer vision, ophthalmology, mathematical chemistry, etc. When you say "no one studies that kind of thing anymore", perhaps you mean it as a shorthand for "no one of any importance", because those other fields are not important? —David Eppstein (talk) 00:05, 25 August 2020 (UTC)

In the same time frame, there appear to be at least several thousand results on google scholar for "mirror symmetry" "conjecture", and even more if you include adjectives such as "geometry." Perhaps Branko Grünbaum would find this an affront, but I'm not particularly concerned with what a single individual from outside the pure maths community thinks thought about modern differential geometry, which appears to be what he is decrying in the introduction to that article. Perhaps he wasn't aware that the universe is described by such useless concepts, or disagreed that that is an important thing to study.

I was merely reporting on the status of the term within the pure mathematics research community. If your objection is that I used the term "mathematical community" instead then fair enough. I have no intention of debating who is or isn't a mathematician or what is or isn't important mathematics. It is probably correct that most people, if they were to want to know more about reflection symmetry, would be a bit surprised if they googled mirror symmetry and the page went directly to an algebraic geometry conjecture in pure mathematics, but WP:BUTIDONTKNOWABOUTIT seems to suggest to me this is just the kind of situation for a disambiguation page?Tazerenix (talk) 19:58, 25 August 2020 (UTC)

Yes, the theoretical physics community is very prolific. And claiming not to want to debate who is a mathematician, while in the same breath labeling Grünbaum (of all people!) as a non-mathematician, comes across as simultaneously disingenuous, ignorant, and upping the ante on your unappealing snobbery. —David Eppstein (talk) 20:14, 25 August 2020 (UTC)

I wasn't being snobbish, I was giving the perspective of someone from that area of pure maths (a not irrelevant point of view I would think, given this is literally a discussion about that topic). I didn't call this man not a mathematician (something which you seem to be projecting onto me, perhaps because of your overlapping areas of interest), I said he wasn't a modern differential geometer, which is obviously true given that his interests appear to lie more in computational geometry and convex geometry (his geometric interests in any case), both subjects of considerable interest both before and after his time even within the pure maths community may I add (see for example Hilberts 18th problem). I have no interest in having a debate about who is or isn't a mathematician with you, and I don't think its relevant to this conversation. Clearly people who aren't algebraic geometers have just as much right to google mirror symmetry and come to wikipedia to learn more about the thing they have in mind as algebraic geometers do, and there are certainly going to be much more of the former people, but since there seems to be contention as to the role of the page and its naming, it seems best to me to have a DAG page. I'd prefer not to have baseless accusations be made at my character for putting my input in on the naming of a wikipedia page.Tazerenix (talk) 21:35, 25 August 2020 (UTC)

To be precise, you said that Grünbaum was "outside the pure maths community". Which is both false and ignorant. And your ignorance reflects on how seriously I should take your apparent preference that the mathematical physics meaning of "mirror symmetry" should be the WP:PRIMARYTOPIC. It is reasonable for it to be the topic of disambiguation. It is not reasonable to declare that a narrow group of specialists can monopolize a phrase with a notable colloquial meaning. —David Eppstein (talk) 21:43, 25 August 2020 (UTC)

Of course, specialists will try, but we shouldn't let them get away with it. :-) XOR'easter (talk) 21:47, 25 August 2020 (UTC)

I meant not within the modern differential geometry community, but alas, your mind is made up. I also said it should be a DAG page four times (my remark that I "choose" the MSC page was meant to be if I had to choose one or the other with no DAG option, and of course my comment is not a decision, just a comment representing my own input, which can happily be disagreed with or ignored. Indeed you are probably right that if we had to choose it should go the other way, but as a snobbish pure mathematician who hoards all knowledge and common phrases, changing my mind or engaging in discussion is out of the question)Tazerenix (talk) 21:54, 25 August 2020 (UTC)

Personally I think this would be a good case for a disambiguation page. The elementary concept is vastly more important than the string theorem/algebraic geometry concepts, but the article on the broader concept is not titled "mirror symmetry" and there are other, more common names for that concept. So we are balancing a specialized notion very strongly associated with the name against a much broader notion more weakly associated with the name; I find it hard to see a case for a primary meaning, especially given the search engine results I mentioned. Therefore I propose:

• The current redirect Mirror symmetry should be deleted
• The current disambiguation page Mirror symmetry (disambiguation) (which has a nontrivial edit history) should be moved to Mirror symmetry (where it used to be)
• The pages on the string theory/algebraic geometry concepts should all have hatnotes pointing to the disambiguation page

(Obviously this requires an administrator to actually carry it out.) --JBL (talk) 21:30, 25 August 2020 (UTC)

• We should always put the reader first. A few readers will be professional mathematicians, but most of us thought a Calabi–Yau manifold was a car part. A mixed audience may make different assumptions as to what "mirror symmetry" means. In such case, the best way to avoid presenting anyone with unexpected topic is to put the disambiguation page at the base name. Certes (talk) 21:59, 25 August 2020 (UTC)

Filters in topology

• Filters in topology (edit | talk | history | protect | delete | links | watch | logs | views)

This article was just created by Mgkrupa. We already have an article at Filter (mathematics), which (aside from basic definitions) is mostly focused on their use in topology. I'm a little skeptical that this should be spun out into a separate article, especially so because what's there now falls very squarely on the wrong side of WP:NOTTEXTBOOK. I'm trying to limit my activity here these days, but I'd certainly welcome others' opinions on this. Thanks, –Deacon Vorbis (carbon • videos) 00:30, 20 August 2020 (UTC)

On a side note, it makes extensive use of special Unicode characters, like (U+212C ℬ SCRIPT CAPITAL B) for example, which I'm under the impression should generally be avoided due to rendering support. –Deacon Vorbis (carbon • videos) 00:41, 20 August 2020 (UTC)

My general impression of Mgkrupa's contributions is that they tend to be very WP:TECHNICAL. For subjects that really are technical, this may be ok, but it tends to spill over onto other subjects where the technicality is an unnecessary obstacle (for instance, I had to revert several times Mgkrupa trying to rework the definitions in convex hull to focus on topological vector spaces rather than Euclidean spaces). —David Eppstein (talk) 00:53, 20 August 2020 (UTC)

I have had a view that the focus of the use in topology in Filter (mathematics) is a *problem*. A "filter" is after all a general concept. A filter (in particular an ultrafilter) is also used in abstract algebra in the form of ultraproduct and also is a useful concept in the theory of Boolean algebras (if I recall, please correct me if you know this stuff). It seems natural to have a separate article on the use of a filter in topology in an independent article (in that case, it is essentially equivalent to net but should probably be separated from that). -- Taku (talk) 01:11, 20 August 2020 (UTC)

This would require an expert (not me) but, for example, we might want to mention a result of G.M.Bergman - Ehud Hrushovski, Linear ultrafilters or some other similar results. In any case, the point is that a filter is a general concept. -- Taku (talk) 01:28, 20 August 2020 (UTC)

Another related matter: ultrafilter is a separate article from "filter (mathematics)"; which is not necessarily bad but if we can separate the topology stuff from "filter (mathematics)", then there will be more real estate to merge the ultrafilter article to the filter article. —- Taku (talk) 02:32, 22 August 2020 (UTC)

I don't really think ultrafilters should be merged into filters. There's plenty to say about ultrafilters as a topic on their own. Also the problems studied with regard to ultrafilters tend to have a bit of a different character from those that come up using filters in general. --Trovatore (talk) 22:43, 25 August 2020 (UTC)

Yes, "ultrafilters" certainly makes sense as an independent topic; that does not mean it needs a separate article. For example, "embedding" discusses both embeddings of a manifold and a category; even though there is *plenty to say* about embedding of a manifold (e.g., Whitney embedding theorem). I suppose the problem is that currently filter (mathematics) is somehow underdeveloped than ultrafilter; the latter mentions a filter (in particular an ultrafilter) on a Boolean algebra while the former has nothing on the use in a Boolean algebra. It would be helpful to the readers including non-specialists (like myself) if there is a single article to read on filters as well as ultrafilters; a spin-off of ultrafilter is needed only after that single article becomes too long. It's possible that filter (mathematics) ends up discussing mostly ultrafilters; I don't think that would be a problem. -- Taku (talk) 00:04, 26 August 2020 (UTC)

No, I really don't agree. I feel very strongly that ultrafilters should retain a dedicated article. Ultrafilters come up largely in the context of ultraproducts. They're mostly a technique for getting elementary embeddings. A typical ultrafilter is generally not definable. That's not true at all for general filters, which can easily be definable, and are studied in lots of other contexts. --Trovatore (talk) 00:37, 26 August 2020 (UTC)

I agree with Trovatore. JRSpriggs (talk) 04:12, 26 August 2020 (UTC)

Sep 2020

"Admits"

I'm having difficulty tracking down a good definition for the technical use of the word "admits" for use in the List of mathematical jargon article. (See Talk:List_of_mathematical_jargon#"Admits"). Can anyone provide one, preferably with a WP:RS to support it? -- The Anome (talk) 10:10, 20 August 2020 (UTC)

@The Anome: Although this is a well-used word in mathematical writing, it's not really a technical meaning of the word. Standard dictionaries give entries that are in line with the usage here: e.g., sense 4 in wikt:admit

(transitive) To be capable of; to permit. In this sense, "of" may be used after the verb, or may be omitted.

     the words do not admit such a construction.

–Deacon Vorbis (carbon • videos) 13:09, 20 August 2020 (UTC)

Agree. Paul August ☎ 14:20, 20 August 2020 (UTC)

This is a standard word but not actually a technical term, except possibly in some special cases. Michael Hardy (talk) 17:29, 2 September 2020 (UTC)

Mirror symmetry

Since the old discussion was archived, it seems like the consensus was to either redirect Mirror symmetry to Mirror symmetry (disambiguation) or just flat out delete the Mirror symmetry page so it doesn't have a redirect. Can an admin weight into this? Wundzer (talk) 20:16, 6 September 2020 (UTC)

Draft:Conservative system

For some totally stupid, utterly ill-thought-out reason, I decided to resolve some red-link issues at Talk:Markov odometer by filling in an article for conservative system (which used to be a wildly incorrect redirect to conserved quantity). Recall that a conservative system is that thing that is contrasted with a dissipative system, and that the Hopf decomposition theorem states that every dynamical system decomposes into a conservative part, and a dissipative part. In simplified terms, a system is conservative if and only if the Poincaré recurrence theorem applies. Hopf did his work in the 1930's, Poincare did his work in the 19th century, and I think the core ideas of a conservative system go back into the 18th century. You can type in "conservative dynamical system" into you favorite search engine and see the hits keep on coming. Of course, it has nothing to do with the current political miasma. Despite all this, some nice WPdian decided that the topic was non-notable and lacked a sufficient number of references and moved it to draft space. Here: Draft:Conservative system ... anyone care to, umm, do whatever it takes to do whatever it is that has to be done to move along the process that results in the publication of those kinds of articles that cover basic, remedial topics in mathematics and physics? 67.198.37.16 (talk) 17:54, 12 September 2020 (UTC)

• wow, very nice article, thanks for the efforts Walwal20 ^{talk ▾ contribs} 04:39, 13 September 2020 (UTC)

MathSciNet as a resource

Is mathscinet appropriate as a resource? I am aware that it might dip into "original research" and also that it may be bad because of the paywall/institutional access. Just as hypothetical examples (just in terms of the mathscinet use in and of itself) what would be the appropriateness of the following:

1. using the fact that Yoshikazu Giga has ten articles cited over 100 times on mathscinet as justification of notability for a wikipedia article

2. this kind of sentence in an article: "According to MathSciNet, Yau's article [ref] is the most widely cited differential geometry article of the 1970s."

3. this kind of sentence in an article: "According to MathSciNet, six of the ten most widely cited differential geometry articles in the 1970s were written by Yau."

4. this kind of sentence in an article: "According to MathSciNet, Serre's most widely cited article is [ref]."

Gumshoe2 (talk) 04:24, 13 September 2020 (UTC)

I think the first example is fine; original research and judgment are a basic part of AfD. But the others are OR, and not suited to an article. 2 and 3 look promotional as well, a further strike against them. --{{u|Mark viking}} {Talk} 04:49, 13 September 2020 (UTC)

Thank you for the feedback... I can definitely understand #3 as promotional or at least odd. I'm not sure I can understand the same about #2 though. For instance, what about the following example: giving on the differential geometry page the five most-cited differential geometry articles? This wouldn't seem to be promotional in any sense, and in terms of original research it seems to me to be about equivalent to #1. (As before I'm not suggesting this as an actual good addition for the page, just trying to understand some hypotheticals.) Gumshoe2 (talk) 05:02, 13 September 2020 (UTC)

I think citation counts on MathSciNet are too haphazard to be meaningful: the accuracy of their numbers depends too much on whether the work is in one of the central areas they index everything of versus something more peripheral where only some of the publications get indexed and many of the listed publications don't include references. In this respect they are worse than broader multi-disciplinary databases like Google Scholar where the subdiscipline doesn't affect the level of coverage. I think many mathematicians would take the position that citation counts, in general, are a bad way to measure or justify the importance of a mathematical result or of a mathematician, and should be avoided in principle. The numbers also vary significantly within mathematical subdisciplines, so numbers that might be very high for arithmetic geometry would be uninterestingly low for numerical differential equations, and this variation also means that when someone works in multiple subdisciplines (some of Giga's papers are more numerical, others more theoretical) you will get a skewed idea of which ones are important. Because they're dubiously meaningful, require a lot of subject-specific knowledge to interpret, time-varying, and sourceable only to search engines, I don't think that citation counts belong in articles at all. While I do regularly make arguments about notability based on citation counts in deletion discussions, they don't work well for mathematicians, because the citation patterns in many areas of mathematics lead to numbers that are much lower and less meaningful than in other nearby fields like computer science or physics. When a mathematician does have genuinely high citation counts (like Giga), there is generally also some better reason for justifying the article (like, in his case, being an AMS Fellow). So my answers to your questions are 1. "Sometimes, but you can usually do better", 2. "No", 3. "No", and 4. "No". On the other hand, MathSciNet and zbMATH are genuinely useful for the independent and reliably-published descriptions they provide of publications. The paywall isn't an issue; Wikipedia sources aren't required or expected to be free. —David Eppstein (talk) 05:19, 13 September 2020 (UTC)

Thanks very much for the thoughtful answer and for clarifying on the paywall. (As a side point, I think numerical pde are actually very well represented on mathscinet, much higher numbers than arithmetic geometry, and in the specific case of Giga I'm not aware of any major numerical work.) I am personally in complete agreement with you about the inherent meaningfulness of citation counts, at least that a low count absolutely cannot be taken as proof of insignificance (the converse might be a little more subtle and require some different analysis). I should say my main interest in the question is captured in your sentence

When a mathematician does have genuinely high citation counts (like Giga), there is generally also some better reason for justifying the article (like, in his case, being an AMS Fellow).

As you acknowledge, sometimes there isn't a better reason. In such a case it may nonetheless be clear to me (or someone else), as an expert in some specific fields, that some so-and-so and their work, unrecognized by significant memberships and awards, is very important. Sometimes this isn't reflected by citations, and I suppose I have to give up since individual expertise is encyclopedically irrelevant. But often it is reflected by citations. Should I still give up? (If it helps, one specific example I have in mind is Wan-Xiong Shi, who has in my view one of the approximately 5 or so most significant papers on Ricci flow. This is consistent with mathscinet citations but as far I know not by any kind of professional honors or recognition other than a few NSF grants) Gumshoe2 (talk) 06:03, 13 September 2020 (UTC)

To phrase it a bit more directly- I'd like to understand better the notability criteria for mathematicians who are only known for their research output and are not recognized by professional institutions. Gumshoe2 (talk) 06:08, 13 September 2020 (UTC)

The point about numerical pde was not so much its representation on mathscinet — that's a problem for a different subdiscipline — but that it is a subarea with higher citation counts than more-theoretical topics and so papers in it will appear more important regardless of whether they actually are. As for Wan-Xiong Shi, you can make a case for WP:PROF#C1 using Google Scholar citation counts, but in general the answer to what to do for people with good research output but inadequate recognition for it is: be patient. We are not here to provide that recognition ourselves, but to record it once others do. —David Eppstein (talk) 06:19, 13 September 2020 (UTC)

I see, I'd misunderstood your comment about numerical pde. I would argue that it is relevant that numerical pde is a significantly larger field than arithmetic geometry and that it actually has many more important papers, but I know this isn't the place for it... Anyhow, thanks for the clarification, much obliged. Gumshoe2 (talk) 06:34, 13 September 2020 (UTC)

Draft:Resonant interaction

I've created an article Draft:Resonant interaction and would like to request for a review, and/or for someone to move this to main article space. As this is primarily physics, I've also placed a request at WP:Physics for the same. I'm posting here, because one aspect, the three-wave equation, have seen intensive study, via inverse scattering methods, for the last 5-6 decades by a variety of prize-winning mathematicians. (They have a Lax pair, specifically, a 3x3 Lax pair). (Actually, I'm planning to split the three-wave resonant interaction into it's own article, the Draft:Three-wave equation. It's rather remarkable; the simplified case is solved by the Weirstrass elliptic functions and so has the Eisenstein series g_2 and g_3 as invariants. Apparently, the Diophantine equations show up too, so its rather number-theoretic-ish for something that shows up in non-linear optics, etc. Which is why I post here, and not just WP:Physics) 67.198.37.16 (talk) 21:43, 16 September 2020 (UTC)

Draft:Fake nodes

I came across this article while doing AFC review. I felt that this article will require some specialist review. --Salimfadhley (talk) 12:46, 12 September 2020 (UTC)

@Salimfadhley: I don't really do AfC and I tend to have a somewhat conservative view when it comes to notability, so feel free to take what I say with a grain of salt. But I think this is an easy sources-do-not-demonstrate-notability decline. The "introduced in 2020" with three sources, at least one author common to all of them, is a pretty big red flag. A quick look doesn't really find anything else out there about this, and it just feels like researcher(s) putting their work on Wikipedia. –Deacon Vorbis (carbon • videos) 13:06, 12 September 2020 (UTC)

I have left a comment on the draft that this draft cannot be accepted as an article because of the policy WP:PRIMARY. Since this concept has been introduced this year, it cannot be any reliable secondary source that discuss it. D.Lazard (talk) 13:18, 12 September 2020 (UTC)

@Deacon Vorbis: There are two authors common to all three sources and four authors common to sources no 1 and 3. --CiaPan (talk) 13:57, 12 September 2020 (UTC)

Thank you all for this swift scrutiny. --Salimfadhley (talk) 15:36, 12 September 2020 (UTC)

(Maybe this is already a settled matter) but the issue with the draft is WP:TOOSOON. I can’t think of any instance when a concept in mathematics introduced this recent can have a Wikipedia article. Mathematics develops quite slowly compared to other Internet-age stuff. —- Taku (talk) 03:42, 13 September 2020 (UTC)

Unrelated to fake nodes, but on the same topic of notability and primary sources, some people may want to look at Deformed Hermitian Yang–Mills equation. I added the notability tag in June, wasn't sure what else to do about it. The relevant physics articles (by Strominger, Witten etc) seem to be somewhat well known, but the article is mostly about recent math preprints, one of which is just listed as "in preparation". Gumshoe2 (talk) 03:58, 13 September 2020 (UTC)

I think this is a different case; the topic itself in this case seems notable. According to [14], there is a 2000 paper with over 100 citations that uses the term in the abstract, which suggests the notion is not too soon and is sufficiently well known. That article cites recent papers itself is not an issue and may be a good thing since recent papers are likely up to dates on the current research status. Also, the use of primary sources itself is not an issue if it does not lead to a biased treatment of the topic. (I don’t know enough about the topic to know if the current article is neutral or not). —- Taku (talk) 02:15, 17 September 2020 (UTC)

I think there are some things to say about the topic which could be notable. But even if we were to take as given that the topic itself is notable, the vast majority of the article is about articles from the last three years which have only appeared on arxiv (one of them not even released publicly in any form yet). That is what seems not too good to me Gumshoe2 (talk) 04:49, 17 September 2020 (UTC)

Draft:List of discoveries in mathematics

Hi all. I'm thinking of moving the draft Draft:List of discoveries in mathematics to mainspace. What do the others think? The topic itself seems reasonable except there is an obvious classic problem of: is mathematics inverted or discovered or both ? Since, in Wikipedia, we can't take a side. The draft should be probably named to Draft:List of discoveries and inventions in mathematics or something. Also, "timeline" instead of "list" may better reflect the current structure of the draft. (The draft itself looks incomplete but the development can still continue in mainspace) -- Taku (talk) 02:21, 17 September 2020 (UTC)

The scope of such a list seems ridiculously large. Wouldn’t basically every mathematics article on Wikipedia qualify for inclusion? The creation of any mathematical theory or object is a "mathematical discovery/invention". — MarkH₂₁^talk 02:54, 17 September 2020 (UTC)

In addition to the above, this was more of Diametakomisi's (aka whalestate) garbage (see Wikipedia:Sockpuppet investigations/Whalestate for some of the history. Most of his other junk has been G13ed by now, but apparently this one has been tweaked a bit by others. Seeing as how the clock's been reset, I'd suggest WP:MFD as mostly the creation of a sockpuppet with only minor edits in the mean time, combined with MarkH21's concerns about being way too broad/vague. –Deacon Vorbis (carbon • videos) 03:12, 17 September 2020 (UTC)

I concur with MarkH21 that the scope would be ridiculously large. I'd !vote to delete it at MfD. XOR'easter (talk) 15:05, 17 September 2020 (UTC)

I agree as well. As well as being hopelessly subjective and way too huge in scope, it is partly redundant to articles like History of mathematics and Timeline of mathematics. Reyk _YO! 15:20, 17 September 2020 (UTC)

I agree with the other responders. What the original poster is talking about is nothing less than a list of mathematics. That list is not useful. Mgnbar (talk) 00:30, 18 September 2020 (UTC)

Thank you all for the responses. It seems that Timeline of mathematics already covers the same topic (and is more complete). So I simply redirected the draft to it. To comment on the concern on the scope: it is ok and possible to have an article on a topic of large scope. In fact, timeline of mathematics does have quite a large scope. —- Taku (talk) 21:30, 18 September 2020 (UTC)

Not a great example though. That article makes it seem like 3/8 of the mathematical world in the 2010s was focused on calculating digits of pi, which unfortunately is probably what most of the world believes mathematicians do. — MarkH₂₁^talk 21:33, 18 September 2020 (UTC)

Well, the author of the article does seem to think the calculation of pi is on per with achievements like proving the fundamental lemma. Given the treatment in general mainstream media, I don’t know if that’s a fair view. —- Taku (talk) 21:41, 18 September 2020 (UTC)

Re-insertion of "nationality" column to the table at Fields Medal

The longstanding consensus at Fields Medal since 2014 was to remove the "nationality" column on the grounds of:

1. not providing particularly relevant information for a mathematics award,
2. reducing edit-warring and nonsense.

I had removed the column again after I realized that an IP had added the "nationality" column back into the table in 2019, and I opened Talk:Fields Medal/Archive 1#Removing the entire nationality column where a new editor is adamant on keeping the column. The discussion could use additional input from math editors here. Thanks. — MarkH₂₁^talk 06:40, 18 September 2020 (UTC)

On the basis of the new consensus there, I have nominated the closely related article List of countries by number of Fields Medalists for AfD at Wikipedia:Articles for deletion/List of countries by number of Fields Medalists (2nd nomination). — MarkH₂₁^talk 20:52, 18 September 2020 (UTC)

While we're on the topic, I think most of Ber31's edits of 14 September are unhelpful, but I wasn't sure if reverting is worth it. What are your thoughts? Brirush (talk) 02:37, 19 September 2020 (UTC)

@Brirush: I just took a look at those edits (here is the diff), and I agree that they aren't particularly helpful but I also don't feel particularly strongly for most of it. The note about winners mostly having PhDs in mathematics probably isn't an important fact for the article, at the very least not lead-worthy. — MarkH₂₁^talk 02:56, 19 September 2020 (UTC)

Thanks, that's how I generally felt and why I didn't revert them. I wanted confirmation though.Brirush (talk) 03:23, 19 September 2020 (UTC)

Ultragraph C*-algebra

Could someone with sufficient nous have a look at Ultragraph C*-algebra? To me that is just highly structured barbed wire, and I can't tell whether it's sufficiently distinct from C*-algebra to merit a separate article, or if it should be merged. In any case I suspect it would have to be a lot less technical; it currently looks like the deep end of an advanced text book. --Elmidae (talk · contribs) 04:02, 6 September 2020 (UTC)

These are examples of C*-algebras that generalise Cuntz algebras and the more general Cuntz-Krieger algebras due to Joachim Cuntz and Wolfgang Krieger. There is no accessible introduction to Cuntz-Krieder algebras: the two foundational papers on "topological Markov chains" were published in 1980 in Crelle's Journal and Invent. Math. The general theory is part of C* dynamical systems and the classification of C*-algebras via K-theory (cf George A. Elliott, Mikael Rørdam, Eberhard Kirchberg, et al). Looking at the article, however, it is quite surprising that it has been transferred to wikipedia. The article graph C*-algebra does not seem very readable. The article k-graph C*-algebra is also quite technical. Paul Muhly, Mikael Rørdam, Ruy Exel, Alex Kumjian and Iain Raeburn seem to have been connected with some parts of the theory. (Paul Muhly's interests are quite broad; they include operator theory.) Mathsci (talk) 14:07, 6 September 2020 (UTC)

Upon reading it, it seems like they are a special (distinguished) class of C*-algebras people study. I agree the article could be improved upon, but don't think deleting it is the correct path. Furthermore, if you went to the article's author's page, you would see they are open to suggestions for improvement. I am going to suggestion some improvements they could make so it can be more accessible to a wider wikipedia audience. Wundzer (talk) 20:21, 6 September 2020 (UTC)

It might be worth splitting out the first half into it's own article, the ultragraph. I'm kind-of surprised that's a redlink, since these kinds of structures are not uncommon in machine learning and knowledge representation and deep learning, they're right up there with hypergraphs and generalized hypergraphs aka metagraphs (whoa, more red-links?). Dettaching from the C* aspects might allow it to mature on it's own, without tension with the more abstract nature of operator algebras. Just an idea. (For example, the DPLL algorithm is "just" a way of walking an ultragraph, and pruning away all ultragraph trees, leaving only a densely connected interior. The interior is then solved by exhaustion, and then the remainder is reconnected and solved trivially. Foundational for the Boolean SAT problem.). (FWIW, there is a version of the ultragraph that has m incoming edges (instead of one) and n outgoing edges (same as the ultragraph); it is common in linguistics and in proof theory/theorem-provers (e.g. in natural deduction, incoming is what goes in, outgoing is what goes out; theorem-proving is "just the simple matter" finding a suitable collection of these to form a closed graph), and, in graph software, it's nicer than ordinary graph representations because it has better CPU-cache locality, uses less RAM in many cases, and is easier to traverse with a recursive algorithm. I don't know that it has a commonly accepted name, however. Generalized ultragraph, it would now seem?) 67.198.37.16 (talk) 01:21, 13 September 2020 (UTC)

@67.198.37.16: Hey! This is awesome you know so much about ultragraphs. Would you like to write up the ultragraph page and include all the intuition/applications to computer science you've mentioned. The wiki community would greatly benefit from these additions. Wundzer (talk) 01:04, 24 September 2020 (UTC)

Draft:Three-wave equation

I'd like to request a review of Draft:Three-wave equation and a move to main-article namespace, as appropriate. It is an applied-mathematics/physics article mostly, used in fluid mechanics, plasma physics, electronics and the like, where this is seen. Mathematically interesting because the uniform solutions are given by Lax pairs and are classified by modular invariants. 67.198.37.16 (talk) 14:41, 21 September 2020 (UTC)

Thanks! 67.198.37.16 (talk) 23:48, 24 September 2020 (UTC)

Mandelbrot set

I've tried to do a little work on Mandelbrot set — making notation consistent, streamlining the parts that are supposed to be summaries, etc. Naturally, the article is filled with pretty pictures, perhaps to an overwhelming extent. In particular, the "3D Images" section seems a bit over the top (and maybe OR-ish). Thoughts on how to improve the page would be most welcome. XOR'easter (talk) 02:59, 24 September 2020 (UTC)

Overall I think the following images can be safely removed or brought to a collapsible "Gallery" section:

Extended content
this fractal has its own article

as they are mostly redundant with other images, mainly those in section "Image gallery of a zoom sequence" which is very clean and organized (props to whoever did it), or they are not referenced from the text, or they have marginal importance to the main subject of the article, I believe.

Section "3D images of Mandelbrot and Julia sets" seems to be original "research". While very interesting, I don't think it belongs to wikipedia, so here's my support if you want to delete it... another option is to shorten the explanation text so that it doesn't look and feel like original research, and bundle the images together in a collapsible gallery. Best, Walwal20 ^{talk ▾ contribs} 03:30, 24 September 2020 (UTC)

Thanks. I've removed all but a couple of the images listed above and cut the "3D images" section. I'd have no objection to restoring a shortened and re-bundled version of it if more sources turn up. The topic naturally lends itself to nice pictures, but we need some analysis showing why any particular way of making pictures is significant. XOR'easter (talk) 19:04, 24 September 2020 (UTC)

Here are some ideas for "improvement" with "improvement" in scare quotes:

• Almost all the pictures show a smooth shading, but there is no explanation on how to get the smooth shading. The answer is one can approximate a "continuous" iteration count as $\nu =n+{\frac {1}{2}}\log \log |z_{n}|$ or something like that (I'm working from memory), for the $z_{n}$ being the last one to leave.
• The orbits of the points inside settle down to an invariant measure. What is it? Do the orbits converge to a stable attractor? (they do) What about the unstable, chaotic orbits? What fraction of the interior "C" lead to unstable, forever-ergodic orbits, vs what fraction are in the basic of an attractor? What is the shape of the neutral manifold? (oops redlink, its a synonyn for center manifold) i.e. the set that divides the basin of the stable attractor from the ergodic/hyperbolic attractor? There are many pictures online... The only problem being that "by popular convention", when people say "the Mandelbrot set" they really mean "that algo that draws the exterior in a colorful way". So talking about the interior is perceived by some as off-topic. BTW, the basins of attraction, the measure itself spread outside the M-set.
• Above is talking about the Normally hyperbolic invariant manifold see also stable manifold for an intro. to the concept, which should cross-pollinate with attractor but currently doesn't. Ditto the Normally hyperbolic invariant manifold is written as if the article lives in a vacuum, and fails to mention any of the other articles talking about related ideas.
• One can ask what happens if one differentiates w.r.t. c. There are some interesting results on the second derivative. If I recall, it has countable point-like singularities, and the pictures are pretty, too.
• The "external rays" should be explained. One solves the 2D Laplace equation for boundary conditions 0 at infinity, 1 on the boundary of the M-set. The circle at infinity, the phase, runs zero-2pi and the lines of constant phase are the rays. There was an important paper back at the time that explained the period doubling of rays, e.g. showing how to find rays that pinch off bulbs, etc. That paper does not seem to be cited (after my quick skim). Its nice because its "mathematical" yet relatively easy to understand, starts building a bridge to ergodic theory.

Yes, its a chore to do this but you asked :-) 67.198.37.16 (talk) 00:54, 25 September 2020 (UTC)

Prowling -- Center manifold is OK-ish, Stable manifold is barely more than a stub and should really be moved to Stable and unstable manifolds because it treats both. And appearing out of thin air: Lagrangian coherent structure is 100% pure awesomeness! What I'm saying is that the Center and the stable/unstable articles could be/should be made equally awesome, and that (b) there is a discrete-time variant of these which applies to the M-set and perhaps the M-set article would be a good way to introduce these concepts... 67.198.37.16 (talk) 02:34, 25 September 2020 (UTC)

Fractal measure page?

I was reading fractal-related the articles such as Hausdorff measure and fractal derivative, as well as doing some reading outside of wikipedia on these topics. In this reading, I noticed that many outside sources tend to lean towards a generic "fractal measure" rather than specifically mentioning Hausdorff measure. Indeed, other fractal measures such as packing measures do exist. However, the hausdorff measure is clearly the most used and most notable one, to the extent that I'd be surprised if most other fractal measures would be considered notable at all. So my question is: should fractal measure be created as a redirect to hausdorff measure, being the most significant of the fractal measures? Or does it warrant a small page of its own describing what makes a fractal measure? Is it notable enough on its own? Thanks, _{Integral Python} ^{click here to argue with me} 17:00, 29 September 2020 (UTC)

This is a case for a WP:DABCONCEPT. --Izno (talk) 17:22, 29 September 2020 (UTC)

Thanks! I've gone ahead and made Draft:Fractal measure, we'll see how it goes. _{Integral Python} ^{click here to argue with me} 22:17, 29 September 2020 (UTC)

I think this is good content for its own page but I think "fractal measure" may not be the appropriate primary framing. "Caratheodory construction" may be more appropriate. A standard reference is section 2.10 of Federer's book "Geometric measure theory". See also the page metric outer measure; the section "Construction of metric outer measures" is essentially the same but seems to me like a strange inclusion there; maybe it should be merged with your draft page. Gumshoe2 (talk) 05:31, 30 September 2020 (UTC)

Currently, Draft:Fractal measure never actually says what a "fractal measure" is. Instead, it just says that there are two examples (and we've got long articles on both examples.) Tell us what it is, and give at least one more example that is not one of the conventional two.67.198.37.16 (talk) 19:27, 30 September 2020 (UTC)

That is why I suggest "Caratheodory construction" as a good alternative. As far as I know, "fractal measure" has no particular meaning. Gumshoe2 (talk) 19:32, 30 September 2020 (UTC)

Oct 2020

Discussion for improving the implementation of Infobox mathematical statement at Fermat's Last Theorem

There is a new discussion at Talk:Fermat's Last Theorem#Further improvements on improving the instance of {{Infobox mathematical statement}} that is used at Fermat's Last Theorem. Any input is appreciated! — MarkH₂₁^talk 23:20, 4 October 2020 (UTC)

Requested move notification

This is to notify members of this Wikiprojects that a likely controversial move request of Algebraic character to Formal character is in progress . Your input will be appreciated. Cheers Megan☺️ ^{Talk to the monster} 18:02, 8 October 2020 (UTC)

Van Eck's sequence

The page Van Eck's sequence was proposed for deletion and then de-prod'ed. The sources offered on the Talk page don't look all that great to me: a scatterplot from the OEIS, a StackExchange thread, MathWorks, etc. XOR'easter (talk) 18:42, 15 October 2020 (UTC)

I had this on my watchlist, but missed the de-PROD. I have nominated it at AfD: see Wikipedia:Articles for deletion/Van Eck's sequence. –Deacon Vorbis (carbon • videos) 20:21, 15 October 2020 (UTC)

Latex on section headings

MOS:MATH currently tells us not to use Latex on section headings, "as LaTeX markup does not appear in the table of contents". However, as the following dummy subsections show (see the TOC of this talk page), Latex is rendered correctly on the TOC, at least for me.

Equal or unequal sample sizes, similar variances $\left({\frac {1}{2}}<{\frac {s_{X_{1}}}{s_{X_{2}}}}<2\right)$

Am I missing something? Walwal20 ^{talk ▾ contribs} 01:27, 9 October 2020 (UTC)

(I changed Latex to HTML on t-test anyway, since Latex screwed up the vertical line spacing on TOC.) Walwal20 ^{talk ▾ contribs} 01:27, 9 October 2020 (UTC)

I'm looking forward to seeing the ToC on Tetration ;) - Astrophobe (talk) 02:42, 9 October 2020 (UTC)

I would not want that last to show up in any TOC of interest. --Izno (talk) 04:04, 9 October 2020 (UTC)

I disable TOCs by default, but I still think that to the extent possible section names should be chosen to avoid needing formulas in them. They're going to look ugly in the section header itself no matter how they're formatted. —David Eppstein (talk) 05:34, 9 October 2020 (UTC)

It seems that the issue of latex (and wikilinks) in section headings has been fixed. In fact, there are 3 points: 1/ rendering in the ToC; 2/ link form the Toc to the correct section; 3/ link from an arrow in the watchlist to the correct section. I edit this post as belonging to the last above subsection for testing the third point. D.Lazard (talk) 09:58, 9 October 2020 (UTC)

It appears that the above 3/ does not work correctly with latex (it works with wikilinks). So, at least in this talk page, latex should be avoided in section headings. D.Lazard (talk) 10:10, 9 October 2020 (UTC)

These may work in desktop browsers, but do they work for mobile? We have recently had a discussion about problems with rendering latex formula on different mobile browsers, and there is a phab ticket. Until we can ensure these work for all users on all devices we should keep the MOS unchanged.--Salix alba (talk): 11:08, 9 October 2020 (UTC)

Well, we could remove false statements from MOS without changing the advice given. --JBL (talk) 11:11, 9 October 2020 (UTC)

D.Lazard, point 3 doesn't work for HTML either. I made a dummy edit to test it. Point 2 works for both cases, but it bothers that Latex cause illegible anchors (#Equal_or_unequal_sample_sizes,_similar_variances_%7F'"`UNIQ--postMath-00000009-QINU`"'%7F) whereas HTML yields a nicer one (#Equal_or_unequal_sample_sizes,_similar_variances_(1/2_<_sX1/sX2_<_2)). Walwal20 ^{talk ▾ contribs} 11:53, 9 October 2020 (UTC)

In the absence of new feedback here, I took the liberty to boldly change the wording in MOS:MATH without changing the original advice, as suggested by JayBeeEll above. The MOS now reads: except for section headings, which should use HTML only, as LaTeX markup might cause uneven spacing in the table of contents, as well as the appearance of illegible anchor links to sections. I do agree with David Eppstein that HTML should also be discouraged, but the discussion so far does not raise sufficient consensus on this. Walwal20 ^{talk ▾ contribs} 10:01, 17 October 2020 (UTC)

UNIQ code instead of math rendering

Can someone who know about math rendering please take a look at the "'"`UNIQ--postMath-00000001-QINU`"'?. The group ?'"`UNIQ--postMath-00000002-QINU`"'? " code in Circle of fifths? Thanks. – Jonesey95 (talk) 15:23, 21 October 2020 (UTC)

@Jonesey95: There was some weird conflict with the <score>...</score> being used. Removing them fixed the issue...they even had an odd "scores are temporarily disabled" warning on the rendered page. Probably an issue for phab I guess? You know a lot more about this stuff I think. –Deacon Vorbis (carbon • videos) 15:46, 21 October 2020 (UTC)

phab:T257066 seems to be related to the scores being disabled, but I don't see any mention of conflicts with math rendering. –Deacon Vorbis (carbon • videos) 16:01, 21 October 2020 (UTC)

That is a strange interaction; I think you did the reasonable thing by commenting out the score sections. I added a note to the phab ticket. Thanks for looking at this. – Jonesey95 (talk) 16:15, 21 October 2020 (UTC)

Erdős–Bacon number

Editors are invited to weigh in here on what kind of sourcing should be appropriate for an Erdős–Bacon number. --JBL (talk) 19:22, 23 October 2020 (UTC)

Yau–Tian–Donaldson vandalism on K-stability page

Can I please get some input in the K-stability talk page in reference to the controversy about the resolution of the Yau–Tian–Donaldson conjecture. This is fairly esoteric stuff, so I'm not sure what technical input to expect, but it is a topic of some contension within the complex geometry community and therefore provokes a lot of edits changing credit around (usually from people in Tian Gangs outer circle who attribute equal/all of the credit for the proof of the conjecture to him). Matters are slightly complicated by the fact that the main rebuttal to Tian's claims of a proof are by Chen-Donaldson-Sun themselves here, which makes it seem like a he-said-she-said situation. Just to summarise for those unfamiliar, the substance of the argument is essentially that Tian put up a paper just days after CDS's paper with several key arguments essentially exactly the same as in CDS, and immediately claimed credit for the proof. The Veblen prize in mathematics was awarded to CDS for their proof, with no reference to Tian, and (and I can only speak informally on this rather than provide written sources) the community outside of Tian's inner circle is fairly decided that the credit goes to CDS.

The user in question (I'm not sure if its acceptable to comment on such things, but their IP links to the University of Utah whose maths department has one person in complex geometry who is a postdoc of Tian's) edited the page to remove all credit to CDS (a clearly ridiculous claim that not even Tian himself supports). I don't think it is accurate to simply give equal credit to Tian and CDS without having a lengthy discussion of the controversy, but given the highly technical nature of the contension and the fact that the main rebuttal is from some of the authors themselves, it makes it a bit difficult to accurately and faithfully write up. Any input would be appreciated.Tazerenix (talk) 11:43, 7 October 2020 (UTC)

If I understand well, there are WP:secondary sources that attribute the proof of the conjecture to Chen-Donaldson-Sun (at least Veblen Prize) while no independent source attributes the result to Tian. This suffices to revert the attribution change as WP:OR. However, as the controversy is notable, it seems worth to mention Tian's claim in a footnote. Also, it seems worh to mention Veblen prize to support (source) attribution. D.Lazard (talk) 14:06, 7 October 2020 (UTC)

Tian’s paper is very widely cited, on the same level as Chen-Donaldson-Sun’s. So I believe it should be mentioned. I addressed this in one way on Tian Gang‘s page.Gumshoe2 (talk) 16:37, 7 October 2020 (UTC)

I've added Tian's credit and added links both to CDS's criticism and Tian's rebuttal. Hopefully this resolves the issue.Tazerenix (talk) 14:39, 9 October 2020 (UTC)

@Tazerenix: Your phrasing takes the point of view of Tian, using words that imply that the CDS accusation is dubious ("they have alleged"; "alleged" carries a connotation that the allegation might not be true) while asserting that Tian's response is the more correct version of the story ("Tian has rebutted"; "rebutted" means "definitively proved incorrect"). After an edit by User:Gumshoe2 it also states, in Wikipedia's voice rather than as a disputed claim, that Tian's proof is independent of the others. Is that an accurate and neutral description of this controversy? —David Eppstein (talk) 17:19, 9 October 2020 (UTC)

Rebut means "claim or prove that (evidence or an accusation) is false", so I think it is a neutral word to use. I've removed the word "independently". Gumshoe2 (talk) 17:23, 9 October 2020 (UTC)

Just to be clear, I think it is best to take the perspective that there are papers by Chen-Donaldson-Sun and by Tian which claim to prove the conjecture, and that there is unresolved dispute over Tian's. I think "allege" and "rebut" are neutral words for that purpose but I don't mind anyone else's edit to the same effect. Gumshoe2 (talk) 17:28, 9 October 2020 (UTC)

I had actually thought I was being too harsh on Tian in my wording! I was trying to write it impartially, so if the wording needs adjusting I would encourage someone to improve it! This of course is a matter better discussed on the talk page. I suppose I should remark that Tian's proof is very much not independent mathematically (the details are almost identical in most places, hence the controversy) but I think after Gumshoe2's edits it comes across neutrally. That is to say, the baseline assumption is that Tian's effort to find the proof was independent, and this is what is disputed by CDS (whether or not the details are mathematically independent). I think this is reflected fairly neutrally in the text now. Tazerenix (talk) 18:01, 9 October 2020 (UTC)

"Disputed", as you just used in your comment, is sufficiently neutral wording. Unlike "rebutted" it does not carry the connotation that the counterargument is convincing to all. —David Eppstein (talk) 18:19, 9 October 2020 (UTC)

Thank you for your input and edits!Tazerenix (talk) 18:28, 9 October 2020 (UTC)

I don't think "rebut" is quite as strong as David Eppstein says. Refute means "prove false"; one of my peeves is when people use it to mean "deny" or "contradict". But "rebut" is not quite as strong as "refute". I would take "rebut" to mean something like "present a reasoned argument intended to refute". --Trovatore (talk) 00:17, 24 October 2020 (UTC)

Barnstar

–Deacon Vorbis (carbon • videos)

Hello everyone! I created a barnstar for the Mathematics WikiProject, which currently lives at User:AviationFreak/MathStar and looks like this:

		The Mathematics Barnstar
		For contribs to math articles

I'm posting here to see if people more associated with the project would like this addition - If so, I'll add it to the project page. AviationFreak💬 00:39, 5 October 2020 (UTC)

Looks fine to me. I might have it say "contributions" instead of "contribs"; I don't see why the word benefits from being shortened here. XOR'easter (talk) 00:50, 8 October 2020 (UTC)

The text is customizable; I've just used the message shown here to demonstrate this functionality. AviationFreak💬 01:28, 8 October 2020 (UTC)

Ah, OK, that makes sense. XOR'easter (talk) 17:22, 8 October 2020 (UTC)

I believe most barnstars are five pointed. Paul August ☎ 17:41, 8 October 2020 (UTC)

I was attempting to do something math-related in making this barnstar a Koch snowflake. I believe six is the usual number of points for a Koch snowflake, but if a five-pointed one exists please let me know. Thanks! AviationFreak💬 18:45, 8 October 2020 (UTC)

For what it's worth, I think the Koch snowflake here is a nifty idea. If someone really wants a 5-pointed star, another possiblity might be some tweaking of an appropriate Newton fractal (see thumbnail for example). –Deacon Vorbis (carbon • videos) 19:10, 8 October 2020 (UTC)

I received a barnstar using this exact Koch snowflake image in 2017, so it is already in informal use, at least. Another non-five-pointed star that I've seen used as a barnstar is File:Small stellated dodecahedron.png (although that one does contain numerous five-pointed stars within it). —David Eppstein (talk) 19:17, 8 October 2020 (UTC)

The small stellated dodecahedron is my favorite of the suggestions so far; it's a bit more visually dramatic than the Koch snowflake, and it depends less on color perception than the Newton fractal. XOR'easter (talk) 18:16, 9 October 2020 (UTC)

I hadn't considered color perception - The dodecahedron would probably be a better fit, unless users here really prefer the "flat" barnstar look as opposed to something more 3D-y. AviationFreak💬 01:57, 12 October 2020 (UTC)

As someone who doesn't really care all that much, I prefer the fractal. The dodecahdron's shading makes it fairly complex to parse visually. If fractals are deemed a nope, then maybe a Petersen graph like File:Petersen1 tiny.svg. Headbomb {t · c · p · b} 03:02, 12 October 2020 (UTC)

I think the snowflake one would be a nice addition. I also think it would be nice to have an official mathematics barnstar, as the currently used "E=mc² Barnstar" has a much more physics-feel than math. Walwal20 ^{talk ▾ contribs}

We've had some discussion here; If anyone uninvolved in the discussion wants to add it to the WikiProject page after having read the discussion, I say go ahead. I would ask that you move my userspace page to a page in this Project's namespace. AviationFreak💬 01:47, 16 October 2020 (UTC)

FYI, there already is one for "mathematics and science" at WP:BARNSTAR. And if you don't propose this new, more specific variant at Wikipedia talk:WikiProject Wikipedia Awards, you might get revert-warring if you try to add it to WP:BARNSTAR. (No, I don't approve of that fact, as a WP:NOT#BUREAUCRACY problem, but I've directly run into it before.)  — SMcCandlish ☏ ¢ 😼  05:16, 19 October 2020 (UTC)

I had originally only thought of this as a star for this project, but I do think (as another commenter pointed out) it could be used in some cases instead of the "E=mc²" star, which currently covers a pretty broad range of topics. Nominating at WT:WikiProject Wikipedia Awards. AviationFreak💬 15:02, 19 October 2020 (UTC)

Per request, I came up with this:

		The Mathematics Barnstar
		put your message here ~~~~

– Jerm (talk) 00:15, 21 October 2020 (UTC)

Does this meet satisfactory? I used File:Nuvola apps edu mathematics-p.svg from the project banner. Jerm (talk) 19:17, 21 October 2020 (UTC)

If we are talking about an official barnstar to be listed at WP:BARNSTAR, I'd expect something more than √x. I don't think I can beat the shininess of the Nuvola apps icon, but this is what I got (see logarithmic integral):

		The Mathematics Barnstar
		{{{1}}}

		The Mathematics Barnstar
		{{{1}}}

I think the snowflake one is heading on the right direction. Any thoughts? Walwal20 ^{talk ▾ contribs} 03:26, 23 October 2020 (UTC)

The snowflake is actually heading to the wrong direction if you want an official barnstar at WP:BARN. Barnstars must go according to WP:B2G, but there are no rules for WikiProjects to have their own collection of awards. Jerm (talk) 03:39, 23 October 2020 (UTC)

I'm not quite sure, but I believe the tropical cyclone has 6 points:

		The Tropical Cyclone Barnstar
		{{{1}}}

Also, many barnstars go against the clipart size recommendations too.

I think I can circumvent the main problem by inscribing a barnstar inside the Koch snowflake. If it is almost transparent, it might even look great. I'll leave that to tomorrow tho. Walwal20 ^{talk ▾ contribs} 03:54, 23 October 2020 (UTC)

The Tropical Cyclone Barnstar has five tips. The lightning is clip art, and the majority of barnstars do follow the guidline. Any barnstar @WP:BARN that is on the 1.0 row are older originals approved years ago. Jerm (talk) 04:22, 23 October 2020 (UTC)

Ouch. I'm blind and stupid for misinterpreting it so badly. I'll see what I can do to make it fit the guidelines. Walwal20 ^{talk ▾ contribs} 05:02, 23 October 2020 (UTC)

Walwal20 I'll give leniency since some of the new barnstars have clip art behind the actual barnstar like File:Nuclear Barnstar Hires.png but not the entire background. Even the Tropical Cyclone Barnstar is not exactly a "normal" barnstar either. Just do your best really. Jerm (talk) 05:22, 23 October 2020 (UTC)

Some more possibilities for five-pointed thingies that are at least vaguely mathematical and not just "ooh it's a fractal":

• The Perles configuration
• The recognition sign of the Pythagoreans
• An impossible Penrose pentagram

—David Eppstein (talk) 06:06, 23 October 2020 (UTC)

@AviationFreak: I looked up this alleged "guideline" and as far as I can tell you are completely free to ignore it utterly, a great many barnstars do ignore it utterly, and that's what I recommend. I think your original offering at the top of this section is the best one. Who cares if it has sixfold instead of fivefold symmetry? It evokes the barnstar, it's mathematical, and it has a pleasing simplicity that the others lack. Superimposing a random formula on top of it, in particular, is in my estimation not an improvement.
In short, nice work! I !vote for your original effort. --Trovatore (talk) 07:14, 23 October 2020 (UTC)

• Out of the options given so far, the original proposed barnstar looks the cleanest and least jarring in terms of color & readability. I don’t see much in WP:B2G for guidance (but it does seem to suggest that one has to use File:Original Barnstar Hires.png?). — MarkH₂₁^talk 07:45, 23 October 2020 (UTC)

@Trovatore: & @MarkH21: WP:B2G has been a long-standing guideline for many years. It literally tells you how to make a barnstar and what file to use, and you’re correct MarkH21, you have to use File:Original Barnstar Hires.png. If you see anything that doesn’t use this file at WP:BARN, you are viewing the 1.0 row which are original awards most likely created before the introduction of the guideline. Some were made after but were still put on the 1.0 row. If members choose the snowflake more than anything else, it will be put on WP:BARN but only on the 1.0 row and on a list for remastering until it meets 2.0/WP:B2G. That doesn’t mean though you can’t use it. It just means it’s the original and possibly outdated. I already made a barnstar that meets the guideline, so my version would be put on the 2.0 row next to the snowflake. That would be the outcome if members of this project choose the snowflake, it will be next to a 2.0 barnstar. Jerm (talk) 13:43, 23 October 2020 (UTC)

Frankly, WP:B2G doesn't look like it has any consensus behind it and is little more than one user's recommendation for how barnstars "ought to be" made. After looking at the talk page of the guideline, it looks like a couple other users share my thinking here. In my opinion, barnstar design should be more of an art than a science, with guidelines that reflect that. We don't need specific guidelines telling us which file we must use as our base image - That's what community consensus is for. It seems like a few other users here prefer the original Koch Snowflake design, so I don't think it should be thrown out due to the fact that it uses the "wrong" image. Personally, I would be happy to support any of the barnstar designs suggested by David Eppstein - I think all of these designs would work better than a generic "math thing" superimposed on a clipart barnstar. Mathematics is unique and often beautiful, and I think a barnstar should reflect that. AviationFreak💬 14:42, 23 October 2020 (UTC)

@AviationFreak: That has been a long-standing guideline. Just because you don't like it doesn't give you the right to surpass a guideline for which WikiProject Wikipedia Awards follows. Jerm (talk) 14:57, 23 October 2020 (UTC)

@Jerm: I'd like to point out that I'm only disagreeing with one point of the guideline - I don't think every barnstar should have to use the same image. In most topics listed at WP:BARN, there isn't a very snazzy star-shaped symbol to represent the topic. For instance, Law Enforcement, Christianity, and Football/Soccer don't really have something star-shaped to represent them. In most topics, this is the case. In some cases however, like Mathematics or Tropical Cyclones, a snazzy star-shaped symbol is available for use. In those cases, it should be used. Even if we agree that B2G should be/is an official guideline, I think this still falls under WP:IAR. AviationFreak💬 15:07, 23 October 2020 (UTC)

@AviationFreak: The original Tropical Cyclone was created in 2006. I was not around when that happened and neither was the guideline, and a barnstar is literally File:Original Barnstar Hires.png. I said the snowflake can be added in the 1.0 row, but there also has to be a 2.0/WP:B2G version. Jerm (talk) 15:23, 23 October 2020 (UTC)

Here is a quick sample I made with the snowflake:

File:Testfile89345324.png

— Jerm (talk) 15:53, 23 October 2020 (UTC)

Jerm would it be possible to make the snowflake be in front of the barnstar, maybe with just a little transparency to barely make the barnstar visible? (in your barnstar, it is already in front, right? Just increase the opacity of the snowflake internals.) That could make a very fine barnstar, and would be much better than The Winnowing Fan Barnstar in terms of not hiding the File:Original Barnstar Hires.png completely:

		The Winnowing Fan Barnstar
		message Walwal20 talk ▾ contribs 18:51, 23 October 2020 (UTC)

I'd also like to thank you for your efforts in designing a new barnstar! Walwal20 ^{talk ▾ contribs} 18:51, 23 October 2020 (UTC)

@Walwal20: The Winnowing Fan Barnstar is actually on the "need to be remastered list." As you can tell, there's not much of a barnstar to view, but I will come up with another sample. Jerm (talk) 19:04, 23 October 2020 (UTC)

@Walwal20: Actually, I've been making different styles, but they all look terrible. I don't think I can do any better with the snowflake, sorry about that. @AviationFreak: Since you introduced the snowflake. Is Walwal's version File:Mathematics barnstar2.png good enough for you? Jerm (talk) 20:46, 23 October 2020 (UTC)

@Jerm: I think Walwal's star looks great! AviationFreak💬 20:53, 23 October 2020 (UTC)

@AviationFreak: I've added it to WP:BARN. Jerm (talk) 21:12, 23 October 2020 (UTC)

I don't care for the unmotivated $\int {\frac {dx}{\ln x}}$ superimposed on it. What's that even supposed to be about? --Trovatore (talk) 23:52, 23 October 2020 (UTC)

Judging from this edit, User:Jerm is ignoring both this criticism of its meaninglessness and the ongoing discussion of better alternatives, and pushing forward with this ugly choice because it looks sort of mathy. —David Eppstein (talk) 00:36, 24 October 2020 (UTC)

@David Eppstein: No, I didn't pick the snowflake, participants is this discussion did. As for the math equation, that's a decision for this project to decide. If you're wondering why I just suddenly decided to pick the snowflake despite my opposition, it's because I don't need to make a remastered version that meets WP:B2G when I already made a barnstar that meets it hence the green barnstar above. The snowflake has been added as the original version because this project has chosen it. Jerm (talk) 00:51, 24 October 2020 (UTC)

Btw, If you want to take the snowflake down from the main page, go ahead, I'm not stopping you. I did that out of courtesy. I've already done my part. If you want me to take the snowflake down from the main page, just ask and I'll do it. If you don't like the snowflake, then you should be addressing the person who made it. Jerm (talk) 01:04, 24 October 2020 (UTC)

Don't worry, I took it down. I'm done with this. It seems no one here can't agree on anything. This person wants this, this person wants that, this person likes it, this person doesn't. No, I presented a guideline for which people must follow to make a barnstar. It's literally a "How to" guide and even tells you what file to use, but no, no body wants to follow a long-standing guideline. In response, everyone is suggesting to just ignore it to get what they want. Those kinds of responses I'd expect only from newly registered editors who ignore policy and guidelines, and everyone here should already know what happens to users who continue to ignore policy and guidelines. I'm doing the best I can, but participants are so divided amongst themselves, it's almost impossible to determine consensus. The only thing that was clear enough was the snowflake, but now someone doesn't like the equation or the snowflake itself. I didn't even make the snowflake, it was Walwal20. The green barnstar above, that's the first thing I introduced here. I used the image file from this project banner because a image file from the project banner is the best representation of the topic for which a WikiProject covers. Clearly I was wrong though, but what's even more clear, is the amount of rudeness I have received for my efforts. Jerm (talk) 02:10, 24 October 2020 (UTC)

Hi Jerm, thanks for the efforts. I think it doesn't change the fact that there is a barnstar for mathematics in WP:BARN, which is progress. Also, sorry for the rudeness of our fellow mathematicians. I believe it is all a misunderstanding though, because most people supported the snowflake-only barnstar, not the one with the equation. I took the liberty of making all the changes to reflect this "better" consensus. It has the support of David Eppstein, Deacon Vorbis, AviationFreak, MarkH21 and Trovatore. And since it is placed as a 1.0 (not a 2.0 one), I think Jerm is also fine with it not having 5 tips. Think we can settle with this, right? Walwal20 ^{talk ▾ contribs} 03:05, 24 October 2020 (UTC)

		The Mathematics Barnstar
		{{{1}}}

As for the $\int {\frac {1}{\ln x}}dx$, it really was a sort of random choice. If anyone has a better suggestion, I can implement it. I had also thought of $e^{2\pi i}=1$, but it would remount to the $E=mc^{2}$ barnstar... Walwal20 ^{talk ▾ contribs} 03:11, 24 October 2020 (UTC)

@Walwal20: Thank you and the snowflake is fine now as is anything else for the 1.0 version because a 2.0/WP:B2G version doesn't have to be made when I already made one via File:Mathematics Barnstar.png. And my apologies as well. This discussion wouldn't have dragged on if I just said something a lot sooner. Jerm (talk) 03:16, 24 October 2020 (UTC)

We’re still talking about this? The original is the nicest. The right margin is oddly narrow when there’s no text, but maybe it corrects when a comment is added? —JBL (talk) 13:15, 24 October 2020 (UTC)

Exceptionally young IMO medallists

I have opened a new discussion at Talk:List of International Mathematical Olympiad participants where we have an entire section of Exceptionally young medallists with their date of birth sourced to Wikidata and as such possible violation of our WP:OR policy. Please contribute to this discussion. Solomon7968 05:39, 25 October 2020 (UTC)

Improving rendering of radical symbol

Apparently intended as an inline alternative to <math>...</math>, {{radic}} uses √ and {{overline}} to render square roots, etc. like this: √7, ⁴√3. At least in my web browser, the horizontal and diagonal lines don't actually connect, which to me looks pretty horrible.

Using <math>...</math> renders the same expressions like this: ${\sqrt {7}}$, ${\sqrt[{3}]{4}}$. This should look the same in all browsers.

Deacon Vorbis points out at Template talk:Radic that <math>...</math> syntax currently doesn't work in the Media Viewer extension (the output of which is what you see on English Wikipedia if you view an image on a mobile device) so at least in the short term that method still needs to be used in image captions. But for the majority of uses, which appear in general article text, I would like to replace the instances of {{radic}} (of which I see about 1300 in the September 1 database dump) and √ + {{overline}} (of which I see about 100) with <math>...</math> markup (of which I see about 67,000 instances using \sqrt).

Deacon Vorbis thinks this would be a waste of time, but I'm not asking anyone else to help. What do people here think? Are there any other circumstances where this change should be avoided? Any better alternatives? -- Beland (talk) 17:09, 22 September 2020 (UTC)

I think {{radic}} looks bad enough that it should always be replaced by <math>. More, I think that in articles that need radicals or other mathematical expressions too complicated to render nicely using templates, all mathematics should be formatted by <math>, because otherwise the inconsistencies between formatting of one type of mathematical expression and another using the same variable names but in a different font are worse than the problems caused by Wikipedia's poor implementation of <math>. —David Eppstein (talk) 17:22, 22 September 2020 (UTC)

I 100% agree. We should replace the √ + overline with just √ or with <math>...</math>. Whatever the replacement is, we should get rid of √ + overline which looks awful and can even be confusing (e.g. a reader could wonder whether √a + bi refers to a square root of a - bi). — MarkH₂₁^talk 17:32, 22 September 2020 (UTC)

Eh, I said a hell of a lot more than that it would be a waste of time, and oversimplifying my rationale like that is kind of dishonest. There's just no good reason to kill off {{radic}} – a slight aesthetic shortcoming isn't enough. Basic square roots are fine in running text, as are any basic expressions, and it's a reasonable option to have for editors, and it's extremely widely used. And overall dissatisfaction with {{math}} vs. <math>...</math> isn't what this is about. It's here, and it's widely used, and this isn't about that. It's about {{radic}}. –Deacon Vorbis (carbon • videos) 17:42, 22 September 2020 (UTC)

I did not intend to misrepresent your position; I was just trying to sum up a longer conversation and my apologies if that is not what you meant. I did point you to this thread so you could jump in and speak for yourself, and linked to the other conversation so readers could get more detail. -- Beland (talk) 17:59, 22 September 2020 (UTC)

FTR, for ease of reference I documented what seems to be the consensus position on the √ issue at MOS:RADICAL. I agree with the idea of fully converting articles to <math>...</math> markup for consistency where at least some can't be rendered properly without it, and I've already been doing that while doing unrelated cleanup. If no one objects to this first MOS addition in the next day or two, I'll see if there's any objection to adding that to the MOS as well. -- Beland (talk) 00:56, 24 September 2020 (UTC)

This is complete nonsense. It conflates several issues, and you're ignoring the standing ability of editors to use text-style math rendering in violation of the spirit of MOS:STYLERET. Wholesale conversion to <math>...</math> isn't appropriate, and just finding that a couple people agree with you isn't enough for a change like this. This is not productive. –Deacon Vorbis (carbon • videos) 01:02, 24 September 2020 (UTC)

@Deacon Vorbis: I see you reverted the addition using a minced vulgarity as an edit summary. I don't think this was appropriate, both in terms of civility and because so far editors seem to prefer that solution 3 to 1. This WikiProject and the Mathematics MOS page are the places I can think of that are most likely to find editors interested in these issues. Is there some other forum you think should be alerted to this proposal to test for consensus? -- Beland (talk) 01:13, 24 September 2020 (UTC)

Really? You're going to complain over "BS"? Really? The fact is, you should just drop this. Trying to steamroll longstanding practice by 3 people is not appropriate. This isn't a problem that needs fixing. And I don't have the energy to devote to arguing over this constantly. I'm doing other things here. You haven't even remotely fucking listened to a word I've said in earlier discussions, just plowing ahead with your fingers in your ears, and it's tiring. –Deacon Vorbis (carbon • videos) 01:20, 24 September 2020 (UTC)

As far as I know, Wikipedia:Manual of Style/Mathematics is under control of this wikiproject, so I don't see any other better place to find consensus either.

That aside, the discussion has not been online long enough to establish consensus, I'd say, Beland. Walwal20 ^{talk ▾ contribs} 01:24, 24 September 2020 (UTC)

Let me also add my support to the idea of discontinuing usage of {{radic}} Walwal20 ^{talk ▾ contribs} 01:24, 24 September 2020 (UTC)

It seemed to be snowballing, but shall we give it a week and see if anyone else weighs in? -- Beland (talk) 01:32, 24 September 2020 (UTC)

@Walwal20: You should review WP:CONLEVEL. To wit, no, the manual of style is the community's, not this WikiProject's. (It happens to be the case that editors of this WikiProject are the most likely to care about the guideline in question, but this set of editors is not the entire set of editors who care about the guideline, and accordingly do not get to control what that guideline says.) --Izno (talk) 02:16, 24 September 2020 (UTC)

Izno I'm aware of WP:LOCALCONSENSUS. "in control" was a wrong way to put it. What I meant is that if we get consensus here in the wikiproject, we can boldly edit the MOS/Mathematics; and most probably no one would revert it on the basis of WP:BRD. Walwal20 ^{talk ▾ contribs} 02:21, 24 September 2020 (UTC)

By the way, I did not say that {{radic}} has to be replaced by <math>...</math>. There may be other alternatives, like a bare √ without an overline. Whatever the case, @Beland: you can open a Request for Comment (probably at Wikipedia talk:Manual of Style/Mathematics with a notification here) to establish broader formal consensus. — MarkH₂₁^talk 01:35, 24 September 2020 (UTC)

Ah, thanks for the clarification. I interpreted that comment as applying to no-argument uses like "the radical symbol (√) is..." but it sounds like you also mean to include with-argument expressions like "√2 is an irrational number because...". I'll add a question about that option, and hereby invite editors to point out any other alternatives they like. Just to avoid smearing comments across three separate pages, I'll start the RFC in a subsection below and point to it from the Mathematics MOS talk page. -- Beland (talk) 05:38, 24 September 2020 (UTC)

I agree that {{radic}}'s use should be strongly discouraged, for already-voiced reasons. --Izno (talk) 02:17, 24 September 2020 (UTC)

MediaViewer and <math>

This discussion has highlights the incompatibility of MediaViewer and <math>. This fails even in desktop browsers. I've created a phabricator task for this T263575. I imagine it will take a long time to fix.

p.s. A couple of small math rendering bugs have been recently fixed, T207535 "Rendering of \oinit very dense" is fixed and T148304: "Incorrect spacing for \mathbin and \mathrel", is waiting for the fix to make it through code review. I think some of the backend problems are now fixed which should make simple bugs quicker to fix. --Salix alba (talk): 18:45, 22 September 2020 (UTC)

Ah dear, I'd just filed T263572. -- Beland (talk) 17:54, 23 September 2020 (UTC)

No worries, the bugs have been merged. Great minds think alike. I could not replicate your bug but found one which failed. What mobile/browser were you using? --Salix alba (talk): 21:00, 23 September 2020 (UTC)

I was using Chrome on Android. Interestingly, looking at your example I do see that the equation is missing on Linux Firefox, rather than generating a syntax error. On Android Chrome, though, I don't see a caption at all for your example. 8/ -- Beland (talk) 01:03, 24 September 2020 (UTC)

Radical RFC comments

The following discussion is an archived record of a request for comment. Please do not modify it. No further edits should be made to this discussion. A summary of the conclusions reached follows.

Eight editors supported the proposal; four opposed it. Both sides made compelling arguments. Supporters say that the {{radic}} syntax is a relic of old technology, renders poorly (sometimes with a gap between the symbols), and is less semantically meaningful than <math>...</math> tags, which are designed to render TeX precisely. Opposers say that inline <math>...</math> tags disrupt page flow, are not copyable, and renders in a small font which is inaccessible. Supporters respond that page flow seems to be roughly equally disrupted with both methods, that the LaTeX is indeed copyable, and that the <math>...</math> tags are compatible with screen readers for accessibility.

There were no valid grounds here for me as a closer to discard any views. Therefore, there is consensus that using <math>...</math> tags to render expressions containing radicals is superior to the old {{radic}} option, and the MoS should be accordingly updated. There is no consensus about the "bare Unicode character + no overline" option (e.g. "√2" or "√(a + 1)"), so its use continues to be permitted (status quo). Further discussions may be useful regarding the future of the "bare Unicode character + no overline" option: whether its use is encouraged, accepted, discouraged, or prohibited. Best, Kevin (aka L235 · t · c) 07:44, 26 October 2020 (UTC)

---

Request for comment: Should inline √ expressions be rendered with <math>...</math> like ${\sqrt[{3}]{4}}$ where technically possible instead of with {{radic}} like ⁴√3 (which uses √+{{overline}})? -- Beland (talk) 05:38, 24 September 2020 (UTC)

---

Proposed changes to the section for Wikipedia:Manual of Style/Mathematics#Typesetting of mathematical formulae, concerning "Radical symbol":

The radical symbol Unicode character (√) can be used when only the symbol itself is needed.

When part of a larger mathematical expression, {{radic}} is the best way to write such expressions in HTML, but the result is unattractive due to the hole between the overline and the radical symbol in many web browsers:

√9, ³√27

This method should be avoided whenever technically possible. Instead, use <math>...</math> tags and \sqrt{}, even if inline. For example:

${\sqrt {9}},{\sqrt[{3}]{27}}$

Because of Mediawiki bug T263572, <math>...</math> markup is incompatible with the Media Viewer (used for full-screen image viewing on mobile devices), so until that is fixed, the {{radic}} method should be used in image captions.

---

Further comments by the proposer.

This proposed text does not mention the "bare Unicode character + no overline" option, like "√2" or perhaps "√(a - b)", but this could be added if editors support it.

(Note some editors have already commented at the beginning of this section.)

• Considering the "bare Unicode character + no overline" option...something simple like "√2" is intuitive and clean, and I do see web pages using Unicode in this way, which is probably how it was intended. It bothers me a little that there's no vinculum, but aesthetically it's less bothersome than one with a broken line. In simple situations like "√2" it's not needed for clarity, but in complex situations like "√a - b" it would be ambiguous what's being rooted. Something like "√(a - b)" would resolve that ambiguity, but I would lean toward using <math>...</math> in these situations. Certainly I'd use <math>...</math> for consistent appearance if it had to be used somewhere else in the article. I wouldn't object if other editors want to keep this option, but if it were entirely up to me, I'd probably just use <math>...</math> in all cases where there's an argument, to minimize the number of conventions in use and to improve cross-article consistency of appearance. For the record, I see "√" followed by a digit (0-9) in the September 1 database dump about 970 times (slightly less than the number of uses of {{radic}}, and "√(" about 300 times. -- Beland (talk) 05:38, 24 September 2020 (UTC)

---

Please place your comments below.

• Support using <math> for all radical symbols, except possibly when talking about the symbol itself or in special circumstances where for technical reasons <math> doesn't work (the only circumstances like this that I can think of offhand are when you want to make a wikilink on the formula like √2 or in a reference with both a formula in a title and a link on the title). —David Eppstein (talk) 06:40, 24 September 2020 (UTC)
• Support, though I think the use of (√ + no overline) should be encouraged too, otherwise people who write mathematics in HTML will always have to use Latex for rendering radicals, which seems to break the so-important consistency per MOS:MATH. Walwal20 ^{talk ▾ contribs} 02:15, 25 September 2020 (UTC)

  Beland hope you don't mind, but I made some style changes to the request for comment, to make it easier to find stuff around.
  Also humbly inviting Deacon Vorbis, MarkH21 and Izno to cast their votes officially here, as they were present in the discussion earlier. Best, Walwal20 ^{talk ▾ contribs} 01:54, 25 September 2020 (UTC)

Sure, thanks for that. -- Beland (talk) 17:41, 25 September 2020 (UTC)

• Support - the template {{radic}} seems to be a relic of the time when browsers couldn't render LaTeX properly, and had to generate PNG images for that. Since support is now universal, there's no reason to to refrain from a proper <math>...</math>. Tercer (talk) 10:52, 25 September 2020 (UTC)
• Oppose the radic alternative gives something that can be searched and copied, unlike the math template example. Graeme Bartlett (talk) 11:21, 25 September 2020 (UTC)
  • That's a good point, though I wonder how often that would just work and how often the user would need to transcribe the formula into some other syntax for whatever math tool they are using locally. (Though a working copy-paste would still help in either case.) In the long term, it might be possible to fix this downside by technical means; to get the ball rolling on that I just filed T263869. -- Beland (talk) 17:41, 25 September 2020 (UTC)
    • Please note that copying already works; it gives you valid LaTeX input. Which is what I need anyway, I'm usually copying either from Wikipedia from Wikipedia, or from Wikipedia to a LaTeX document I'm using locally. I'm a bit skeptical about the use case where you would want to copy a formula and have it as anything other than LaTeX. Tercer (talk) 06:49, 26 September 2020 (UTC)
      • Ah, you're right. Highlighting is a bit futzy but is possible if you go a bit further to either side than usual. @Graeme Bartlett: Does that work for you? Maybe I should close that feature request? -- Beland (talk) 04:00, 28 September 2020 (UTC)
  • Search does work for equations in <math> tags, I've used a bit for finding uses of specific latex commands e.g. [15] but its probably useless for trying to find a specific equation. For copying the latex of the equation is available in a hidden span in the source code, I've a short script in my User:Salix alba/vector.js which copies the latex equation from math tags when you double click on the equation, it's quite handy. Vanilla MathJax has a right click menu which allows the equations to be copied to the clipboard, as Latex, MathML or if present any annotation text. This seems to have gone from our system. --Salix alba (talk): 17:38, 27 September 2020 (UTC)
• Per my comment above, support. --Izno (talk) 14:45, 25 September 2020 (UTC)
• Support: As with my pre-RfC comment, I 100% agree. We should replace the √ + overline with just √ or with $...$. Whatever the replacement is, we should get rid of √ + overline which looks awful and can even be confusing (e.g. a reader could wonder whether √a + bi refers to a square root of a - bi). The proposed MOS change shifts preference to the LaTeX for most purposes but does not explicitly forbid {{radic}} and √ for cases when copy-ability is necessary. — MarkH₂₁^talk 06:58, 26 September 2020 (UTC)
• Support<math>...</math> is much nicer looking and also more semantically meaningful than {{overline}}. Jackmcbarn (talk) 16:46, 27 September 2020 (UTC)
• Support This is not a radical proposal. Bubba73 ^{You talkin' to me?} 04:03, 28 September 2020 (UTC)
• Strongly oppose For inline mathematics. Do none of you realize you can't copy and paste those characters, they mess up the flow of text. There must be a better option than using rendered PNG files to display inline math. Footlessmouse (talk) 07:12, 10 October 2020 (UTC)

  As we discovered above, you actually can copy-and-paste the rendering of <math>...</math> markup. -- Beland (talk) 15:38, 11 October 2020 (UTC)

  Which plays better as part of a line of text: ⁴√3 or
  ${\sqrt[{4}]{3}}$? To me they look about equally disruptive to the spacing.
  I don't think there's a good way of writing exponents in big blocks of texts. - Astrophobe (talk) 01:56, 12 October 2020 (UTC)

• Support I appreciate that math mode has downsides, but in my opinion the existing radic solution that cobbles together multiple symbols that visibly do not even line up is just too janky. - Astrophobe (talk) 01:53, 12 October 2020 (UTC)
• Support seems to be strong, so I reimplemented the proposed change, and will start fixing articles. -- Beland (talk) 02:41, 18 October 2020 (UTC)

  Well, I was reverted by User:Deacon Vorbis who said the above results don't represent a consensus, so we'll await a formal closure by someone else. -- Beland (talk) 06:24, 18 October 2020 (UTC)

  I am happy to close this, unless someone gets there before me. — Martin (MSGJ · talk) 12:58, 18 October 2020 (UTC)

  @MSGJ: Go for it. --Izno (talk) 13:19, 18 October 2020 (UTC)

• We prefer simple text for simple expressions, radicals included. This has been common practice, and trying to force use of <math>...</math> for this one case is a horrible idea, and there's nothing to fix. It's one thing if you want to recommend the use, but any large-scale changes away shouldn't be done. –Deacon Vorbis (carbon • videos) 13:25, 18 October 2020 (UTC)

The proposal was not for two markup methods from which editors could choose one and then we'd not change back and forth. It was definitely not to retain the status quo. It was to use the <math>...</math> markup method wherever technically possible. Your personal opposition to the proposal is noted and understood, but a supermajority of editors commenting on the RFC did not agree with your position. -- Beland (talk) 17:22, 18 October 2020 (UTC)

• Oppose per Graeme Bartlett (search concerns) and for MOS:ACCESSIBILITY reasons; the <math> version results in some elements of the results being tiny and hard to read.  — SMcCandlish ☏ ¢ 😼  05:08, 19 October 2020 (UTC)

  Perhaps you could give some examples of your accessibility concerns, as no one else has mentioned this? For example how does ⁴√3 compare with ${\sqrt[{4}]{3}}$? — Martin (MSGJ · talk) 10:31, 21 October 2020 (UTC)

  For me, the degree (in this case "4") renders at about the same size in both instances, though in a different font. They are smaller than the main text, but that's how the notation works. If the <math>...</math> rendering is hard to read, then perhaps we should increase the font size that the rendering engine puts out. There are over 21,000 expressions that use this markup in the October 1, 2020, database dump, and it's not feasible to stop using that method for complicated expressions. We could also advise people who find any part of an article difficult to read to increase the zoom level on their browser (that works for me), though I do try to remove things like CSS that sets the font size at 80% and whatnot for this same reason. -- Beland (talk) 17:56, 21 October 2020 (UTC)

  Perhaps there are differences in how screen readers interpret each rendering. Does anyone have any info on that? — Martin (MSGJ · talk) 21:32, 21 October 2020 (UTC)

  Help:Math says the hidden MathML generated by <math>...</math> markup is compatible with screen readers. -- Beland (talk) 22:58, 22 October 2020 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Bogdan Suceavă

I can't judge Bogdan Suceavă's notability as a writer, but despite the long section on his mathematical career, it seems to include little that would count as notable by usual wiki standards. Just passing it along in case someone would like to improve it. Gumshoe2 (talk) 03:44, 26 October 2020 (UTC)

Perhaphs the most interesting thing is the paper he wrote on Nicole Oresme and development of the concept of curvature. The history of curvature is a subject where we are sadly lacking.--Salix alba (talk): 09:02, 26 October 2020 (UTC)

Radon–Nikodym theorem

I think I'd appreciate some help/advice with the Radon–Nikodym theorem article. I'm wanting to avoid a slow-motion edit-war and seem to have ended up in paralysis.

In August, an unnamed user edited the proof, which meant that when I came to read it (for the first time) shortly afterwards it seemed to me to be invalid. The previous version seemed basically okay, so I reverted the edit, adding an explanation at Talk:Radon–Nikodym theorem#Reverting proof to include Hahn decomposition. A while later, this was re-reverted anonymously by a different IP address (though quite possibly the same person), with no discussion.

At that point, I decided the best thing I could do was to add some extra detail to the Talk page expanding on my concerns, and to leave the main article untouched in the hope that a third editor might provide a fresh view. That was on 8 October 2020 and in the meantime nothing has happened. I'm not sure where best to go from here, so we end up with a reliable version. Any suggestions or comments would be very welcome. Thanks, NeilOnWiki (talk) 08:45, 23 October 2020 (UTC)

I suggest you just revert or edit to what you want. The anon editor may no longer be around. If he is, take it to the talk page of the article and see if you can get consensus. --Bduke (talk) 08:58, 23 October 2020 (UTC)

Thanks. I've given that a go, (re-)reverting and adding some motivating comments to the part of the proof that was (I think) wrongly edited. The terse style of mathematical proofs tends to make them read like they were beamed down from outer space, so I hope some commentary may be more generally helpful, too. NeilOnWiki (talk) 21:11, 26 October 2020 (UTC)

Subgroup and other notations

I am rewriting List of mathematical symbols. In the current version and in Subgroup, it is asserted that ≤ and < are "commonly used" for denoting respectively a subgroup and a proper subgroup. I am convinced that some authors used this notation, but I am not sure whether this is sufficiently common for being mentioned. I am unable to test this with a Scholar Google search. Does this meaning of the inequality symbols must be kept, or must it be removed per WP:UNDUE.?

I have similar questions for the use of $\leqq$ with a different meaning from $\leq$ (for vector inequality), and for the use of $\ll$ for absolute continuity in measure theory. D.Lazard (talk) 10:24, 21 October 2020 (UTC)

I had a look at some standard abstract algebra references (Lang's Algebra, Pinter, Artin) and they don't seem to use < and ≤ for subgroups, and shockingly, even some more modern references (Aluffi Chapter 0, the stacks project) appear not to use this notation. I find this quite bizarre, as I have found it to be quite common (it has appeared frequently in lectures and courses I have attended for example). Since it doesn't appear to be well represented, I suppose it could be removed from the < and ≤ parts, but I think one then should add it to the ⊆ ⊂ section separately to subset (as these references certainly do use set notation to indicate subgroups in this way). Perhaps one could even put a small note there that < and ≤ are sometimes used.

On the other hand, $\ll$ is definitely common for absolute continuity of measures (for example it is used in Stein-Shakarchi Real Analysis and Rudin Real and Complex Analysis, two standard measure theory references). I have no comment about $\leqq$ for vector inequalities, this doesn't seem to be common.Tazerenix (talk) 12:03, 23 October 2020 (UTC)

I have frequently seen ≤ and < as notations for subgroups. It is the standard notation in Abstract Algebra by Dummit and Foote and Group Theory by Scott, for example, and is common enough to be mentioned (in my person experience). — MarkH₂₁^talk 19:13, 28 October 2020 (UTC)

I can confirm that ≤ and < are fairly common notation for subgroups, including in group theory papers (as well as textbooks). I don't think that the comment that it's rarely used outside of elementary group theory is accurate: Aschbacher's Finite Group Theory (a central and very non-elementary text) uses it, for example. Russ Woodroofe (talk) 20:42, 28 October 2020 (UTC)

@D.Lazard: Adding to what Russ Woodroofe has said, the notation is used in a wide variety of topics outside of elementary group theory. For example:

• group theory paper
• group theory paper
• combinatorics paper
• model theory paper
• algebraic topology paper
• automorphic representations textbook (e.g. page 8)
• topological automorphic forms book
• algebraic number theory paper
• algebraic number theory / automorphic forms paper (in Ann. Math.!) (e.g. page 1649)

— MarkH₂₁^talk 07:05, 29 October 2020 (UTC)

OK, I have removed the disputed sentence. However, I have replaced "means" by "may mean" for suggesting that this is not a universally accepted notation.

By the way, a fundamental issue of the previous version of the article article was that there were no indication whether symbols and their meanings are standard, commonly used, rarely used, or specific to few authors. IMO, this may be an important question for users of this page. So, for most symbols, I have to do some bold choices. When my choice is wrong (as for < and ≤), the new structure of the article makes easy to fix my mistakes. D.Lazard (talk) 08:46, 29 October 2020 (UTC)

Thanks for the change, and thanks for the overhaul of the article in general! A lot of these math list articles need proper rewrites. Ideally, we can also add citations to several of the statements in the list. — MarkH₂₁^talk 08:49, 29 October 2020 (UTC)

Nov 2020

MOS:MATH#Blackboard bold

This section of the manual of style does not takes into acoount the improvement (over the years) of the rendering of Latex in WP, nor the fact that the use of blackboard bold for the basic number systems is presently a standard in mathematical articles. Also, the rendering in Unicode of blackboard bold is definitely awful, even when using {{math}} environment (see, for example, Quaternion#Algebraic properties).

So, I have written a new version of this section that can be found at user:D.Lazard/Blackboard. My question is: is this new version worth to replace the old one? In any case, be free to improve my poor English. D.Lazard (talk) 16:50, 1 November 2020 (UTC)

I disagree that blackboard bold for the basic number systems is presently a standard in mathematical articles. You need to prove that. --Trovatore (talk) 18:24, 1 November 2020 (UTC)

I agree that the Unicode blackboard bold is awful and to be avoided. If we are to use blackboard bold for the basic number systems (which I think is pretty common, at least, regardless of whether we can call it "a standard") we should use <math> not templates/html. —David Eppstein (talk) 19:52, 1 November 2020 (UTC)

Right, so there are two rather separate issues, one being whether BBB ought to be encouraged if it rendered perfectly, and one being the current state of rendering.

On the current state, <math> is a lot better than it used to be, but sizing issues can still be a little distracting.

On the more central issue independent of rendering, it's certainly true that there is a considerable amount of published material that uses BBB, especially for the real, natural, and complex numbers.

I learned real analysis from Folland, which uses ordinary bold, and I personally find that more graceful. It is true that there are situations where you might reasonably want to use (say) R as a variable, and in those situations it's useful to have $\mathbb {R}$ available. But in origin $\mathbb {R}$ is just a way of writing R on a blackboard without using so much chalk.

I guess part of what bothers me about wide use of BBB is the danger of contributing to the perception that these sets have once-and-for-all symbols that are used universally, which just isn't true. --Trovatore (talk) 20:06, 1 November 2020 (UTC)

(edit conflict) Blackboard bold is certainly a standard (alongside boldface) that is commonly used in math articles. Just take a look at Annals's most recent issue (Volume 192 Issue 2): 7 of 8 articles used blackboard bold, 1 of 8 articles used boldface. — MarkH₂₁^talk 20:12, 1 November 2020 (UTC)

It's a standard in the sense that it's widely understood. I was probably taking D.Lazard to be saying something more like it was the standard, which may not have been what he meant. But that's really my concern; we should not be promoting it as the standard. --Trovatore (talk) 20:28, 1 November 2020 (UTC)

It might not be the standard (although if it isn't, it's still the clear majority). I don't see the draft at User:D.Lazard/Blackboard as promoting it as the standard though. It says to use the Latex rendering [...] or the standard boldface and discourages the Unicode blackboard bold characters. — MarkH₂₁^talk 20:42, 1 November 2020 (UTC)

Regarding the original question, I think that the draft is a suitable replacement / expansion of the current MOS:MATH#Blackboard bold (perhaps without the mainly in elementary textbooks claim). — MarkH₂₁^talk 20:59, 1 November 2020 (UTC)

Should it mention that $\mathbb {E}$ is sometimes used for expected value? I think it is not as standard, but it does appear in some of our articles, e.g. Pearson correlation coefficient. —David Eppstein (talk) 22:42, 1 November 2020 (UTC)

There are other uses. Some are listed in the current version of List of mathematical symbols, where $\mathbb {A} _{n}$ (for the affine space of dimension n) is omitted. This is by thinking how presenting blackboard bold in the new version of this list that I came to the conclusion that MOS:MATH was definitely of no help for this matter. D.Lazard (talk) 11:52, 2 November 2020 (UTC)

I'm not sure it's useful to say that Blackboard bold typeface was never used in traditional typography. What counts as "traditional"? And the history of blackboard bold is better addressed in the article on it than in the Manual of Style. I'd collapse the first two sentences to Blackboard bold typeface was introduced to more easily distinguish boldface from ordinary lettering on a blackboard. XOR'easter (talk) 19:17, 2 November 2020 (UTC)

In general I don't think the "it was originally intended as synonymous with X but diverged" is useful as guidance on current style. We could say the same about "u" versus "v", or about capital and lower case letters being used together and meaning different things rather than just being different ways of writing the same letters. —David Eppstein (talk) 20:22, 2 November 2020 (UTC)

I guess I think it's sort of bad to use bbb distinctively from bold. How are you going to represent that on an actual blackboard?

Granted that it's not our place to either drive or impede language change. But I think we should err to the conservative side when necessary. --Trovatore (talk) 20:35, 2 November 2020 (UTC)

It's also bad to use letters with curves in them like u instead of v. Because how are you going to chisel that into stone? —David Eppstein (talk) 21:30, 2 November 2020 (UTC)

Blackboards are still in use. --Trovatore (talk) 21:33, 2 November 2020 (UTC)

So are engravings into stone. But not as a medium for viewing Wikipedia articles. —David Eppstein (talk) 22:42, 2 November 2020 (UTC)

My point is that if you're using $\mathbb {R}$ specifically to be able to distinguish it from R, that's probably not an optimal habit to get into, because it'll be difficult to present on a blackboard, even if it works fine in an online resource. Blackboard bold really should be thought of as a way to do bold on a blackboard. Then if you also want to use it in print, fine, but using it distinctively is probably not a great idea. --Trovatore (talk) 22:53, 2 November 2020 (UTC)

If you really think that blackboard bold can only be a way to make boldface look more legible then why do you want to deprive Wikipedia readers of the same benefits of legibility by discouraging its use? Surely it would be more consistent to forbid boldface and just use bbb for everything that you want to embolden. —David Eppstein (talk) 23:14, 2 November 2020 (UTC)

I never said it was a way to make it more legible. I said it was a way not to use so much chalk. (I didn't mention the time it takes to put a bold letter on a chalkboard; that's actually probably even more important than the amount of chalk.) --Trovatore (talk) 23:18, 2 November 2020 (UTC)

So we should avoid a convenient notation in our Wikipedia articles because chalk is expensive? Or because you never learned to use beamer to format projector slides with LaTeX? Those don't seem like particularly principled or relevant objections to me. —David Eppstein (talk) 23:24, 2 November 2020 (UTC)

I do in fact know how to use beamer. It's not great for free-form discussions, though.

Aesthetically it just seems off to use a notation for rendering bold on blackboards as though it were semantically different from bold. It's like using $\phi$ distinctively from $\varphi$. Even if you can come up with situations where that would be convenient, it's still a bad idea. --Trovatore (talk) 23:31, 2 November 2020 (UTC)

Merger of maths rating and maths banner

Look, I am not a participant of the maths project but I like to have the templates {{maths rating}} and {{maths banner}} to be merged into one à la all the WikiProjects. The merged version can be found at Template:WikiProject Mathematics/sandbox and testcases can be found at Template:WikiProject Mathematics/testcases. --Soumya-8974 ^talk _contribs ^subpages 17:49, 22 October 2020 (UTC)

This is feasible at some point in the future, should the project want to. But the code in that sandbox is not quite right, and I would want to check a few things first — Martin (MSGJ · talk) 18:53, 25 October 2020 (UTC)

@Soumya-8974: I think the most sensible direction to merge this in the first instance is to {{maths rating}} as that is the older template with more history. I have added the required quality classes and functionality to Template:Maths rating/sandbox, and Template:Maths banner could potentially be redirected to Template:Maths rating with barely any noticeable change — Martin (MSGJ · talk) 20:48, 1 November 2020 (UTC)

You're right. I proposed to merge {{maths banner}} to {{maths rating}}, delete {{WikiProject Mathematics}} and move {{maths rating}} to {{WikiProject Mathematics}}. --Soumya-8974 ^talk _contribs ^subpages 04:58, 2 November 2020 (UTC)

The first part of this is now done and I will leave it to someone else if they want to open a [WP:RM]] on {{maths rating}} — Martin (MSGJ · talk) 12:13, 3 November 2020 (UTC)

I agree with some kind of merge, it's not clear to me if there is a reason for keeping a separate template for pages outside article space. No comment on how it should be carried out. — MarkH₂₁^talk 20:52, 1 November 2020 (UTC)

Wikipedia:WikiProject Mathematics/Assessment

When I look at Wikipedia:WikiProject Mathematics/Assessment I see a table with 17,771 articles in it. If I look at Wikipedia 1,0 Server - Mathematics I see a similar-but-different table with 20,871 articles in it. It's missing the "unassessed" and "unrated" columns; it adds a few others. Since the total is larger, I assume that the first is many years out of date, and that the second is updated daily. 67.198.37.16 (talk) 17:18, 5 November 2020 (UTC)

Since you are seem to be continuing to edit in areas related to ergodic theory, can I just add a comment on sources? The topic started around 1931–1932 with von Neumann and Birkhoff (working in competition, as you can read from recently published letters). It's probably worth adding more references for ergodicity. I have added a list of citations for ergodic flow, an article which I am currently rewriting to simplify the presentation (flows built under a ceiling function were first invented by von Neumann in his 1932 Annals paper and his construction was essentially operator-theoretic). The books of Petersen, Walters, Nadkarni, Pollicott & Yu and Cornfeld, Fomin & Sinai are all useful references. Unfortunately there is no translation of von Neumann's original paper (George W. Mackey has made summaries of it in his lecture notes). The 1960 book of Jacobs is in German and uses convexity to avoid using the spectral theorem. For invertible measure-class preserving transformations, anything by Rohlin, Furstenburg, Ornstein or Weiss is valuable, particular the material on Bernoulli shifts and entropy: the complete 1966 notes of Rohlin are available on google books. Mathsci (talk) 19:08, 5 November 2020 (UTC)

User:WP 1.0 bot/Tables/Project/Mathematics is updated daily so I have replaced with that one — Martin (MSGJ · talk) 20:33, 5 November 2020 (UTC)

Proposed change to Template:Maths rating from 2018

Per this Phabricator task, User:MusikAnimal in October 2018 requested that this template be changed to use {{WPBannerMeta}} so that the assessments are compatible with XTools. However, it got ignored because there were so few people watching the page, so I'm pointing it out here per the comment. Could someone with template-editing power please take a look at this? Thanks. Ionmars10 (talk) 12:30, 17 September 2020 (UTC)

I'm starting to look into this. If anyone want to as well, please feel free. –Deacon Vorbis (carbon • videos) 13:11, 17 September 2020 (UTC)

I think {{class mask}} is what does the normalization, so it should be enough to simply pass the class value through it when storing it via the #assessment parser function. But converting the whole template to use {{WPBannerMeta}} is better to be consistent with other WikiProject banners. — MusikAnimal ^talk 13:35, 17 September 2020 (UTC)

Yes, please kill this non-standard banner and have {{WikiProject Mathematics}} handle both what {{Maths rating}} and {{Maths banner}} currently do. There is no reason for the two distinct templates. Headbomb {t · c · p · b} 18:19, 22 September 2020 (UTC)

What matters to me on this is that we continue to use the "priority" field rather than "importance". As long as we don't start using "importance", I have no objection. --Trovatore (talk) 18:26, 22 September 2020 (UTC)

You can easily rename the parameter with |IMPORTANCE_SCALE_NAME=priority or something similar (the parameter name might have changed), User:MSGJ would know. Headbomb {t · c · p · b} 00:35, 3 October 2020 (UTC)

Really it ought to be globally renamed to "priority". Calling it "importance" was always an extremely bad choice. But at least for this project, we should uniformly use "priority". --Trovatore (talk) 04:52, 7 October 2020 (UTC)

There is a meta-enabled version in the sandbox and some testcases at Template:Maths rating/testcases. I agree completely with your view of priority/importance and the meta-template supports priority, although sadly yours seems to be the only project still using it. The categories are currently using the lower-case version (priority instead of Priority) but this will be simple enough to fix. — Martin (MSGJ · talk) 12:26, 8 October 2020 (UTC)

Seems to work but does look considerably different. --Salix alba (talk): 19:59, 8 October 2020 (UTC)

What is even the point of the illegibly tiny 10-pixel-or-so head of Blaise Pascal next to the field? Is it there because the space looked empty below the big colored banners for quality and priority? To me it looks worse than having nothing at all there. —David Eppstein (talk) 20:16, 8 October 2020 (UTC)

I have removed the custom size so it now shows the default 25px. Is that better? It can of course be removed altogether. — Martin (MSGJ · talk) 07:57, 9 October 2020 (UTC)

The differences are pretty much cosmetic. One thing though, @MSGJ:, the 'history' thing should probably be handled like another taskforce, rather than be shoved in the 'additional information' part of the template. Headbomb {t · c · p · b} 20:20, 8 October 2020 (UTC)

It seems the |historical= parameter can be set regardless of the field and is independent of |field=history. Is that really desirable? I suppose it would be redundant to use both at the same time. — Martin (MSGJ · talk) 07:57, 9 October 2020 (UTC)

The conversion seems to have gone well. I have a few questions:

• |historical=yes triggers Category:History of subject mathematics articles and |field=history triggers Category:Mathematics articles related to history of mathematics. What is the distinction between these and can they be merged into one?
• |frequentlyviewed= was set by VeblenBot which hasn't edited for several years. Should this feature be dropped?
• Is there ever a need to identify an article as being within more than one field, e.g geometric group theory should probably be tagged as geometry and algebra — Martin (MSGJ · talk) 15:10, 13 October 2020 (UTC)

  History of mathematics is a field of academic study concerning the mathematics of the past. It is a different thing than topics within mathematics which have themselves become historical or obsolete. And yes, whenever there are boundaries, there are boundary cases, topics that cross those boundaries. Topics that cross multiple projects are handled by having multiple banners. Without being able to list articles as being in more than one field how would we handle topics that cross multiple fields within mathematics? —David Eppstein (talk) 16:55, 13 October 2020 (UTC)

  Just as I thought. So instead of using two different banners, which is very clumsy, a better syntax would be {{maths rating|algebra=yes|geometry=yes}}. Do you agree? And thanks for the explanation of the difference between history and historical - I will try and clarify the documentation — Martin (MSGJ · talk) 18:38, 13 October 2020 (UTC)

Page assessments

I'm not quite sure why {{Maths rating}} is not working with XTools. Looking at mw:Extension:PageAssessments for assessment to work it requires the {{#assessment: <name of the wikiproject> | <class> | <importance>}} parser function. Looking at the source of math rating template the necessary code is there. --Salix alba (talk): 08:17, 7 October 2020 (UTC)

Looks like the problem might have been that XTools requires the class/importance values to start with an upper case letter. I've edited the template to ensure this happens and on the couple of pages I've tested the XTools results seem to be working now. See for example XTools|Carry (arithmetic). Other articles will take longer for the job queue to do its job. If you want to hurry things along a null edit will make things change instantly. --Salix alba (talk): 09:20, 7 October 2020 (UTC)

More questions about project banner

• All the mathematics field pages (e.g. Wikipedia:WikiProject Mathematics/Wikipedia 1.0/Number theory) are marked historical since 2012. Should they be removed from the template?
• The most frequently viewed articles are based on a list compiled in 2009. Can this be updated or should be field be removed?
• The A-class rating page is marked historical since 2015. Should this parameter also be removed?

— Martin (MSGJ · talk) 22:44, 27 October 2020 (UTC)

I have removed these features from the template now — Martin (MSGJ · talk) 15:41, 29 October 2020 (UTC)

I think it is nice to have "frequently viewed" in the banner itself. It has the subtle psychological impact that, when you see it on the talk page, it reminds you that school-students and home-makers are reading the article, and you should shift perspective and tone appropriately. In contrast to, say, DF-space, which is a safe space to geek out. 67.198.37.16 (talk) 18:35, 5 November 2020 (UTC)

Yes, it would be nice if we had any confidence in the reliability of the data ... Unless there is a more up-to-date list I don't think we should use the list from 2009 — Martin (MSGJ · talk) 20:34, 5 November 2020 (UTC)

Field no longer showing

The current banner no longer displays the field, which seems awkward. Will it be restored? Also, I'm not sure I like the multi-field proposal {{maths rating|algebra=yes|geometry=yes}} above; math being what it is, most articles will end up within half a dozen different fields. 67.198.37.16 (talk) 18:24, 5 November 2020 (UTC)

I removed them because, as noted above, the corresponding project pages have been marked historical for the last 8 years. However the data is not lost and the field can be restored again if the project wishes. (But we should probably unmark them as historical in that case.) — Martin (MSGJ · talk) 20:37, 5 November 2020 (UTC)

Category:Lists of mathematics articles

I have been trying to do some tidying in Category:WikiProject Mathematics and moving things to subcategories. One of these subcategories is Category:Lists of mathematics articles which I populated with Wikipedia:WikiProject Mathematics/List of mathematics articles (A) through Wikipedia:WikiProject Mathematics/List of mathematics articles (Z). Unfortunately I keep getting reverted by Mathbot, and its operator Oleg Alexandrov has suggested that I post here. Does anyone have any objections to this categorisation or suggestions for better names? — Martin (MSGJ · talk) 12:48, 19 October 2020 (UTC)

Articles that aren't in the mainspace shouldn't be in categories that look like they are intended for mainspace. That's my only comment on the matter. Category:WikiProject Mathematics lists would be fine. Otherwise, I agree they should probably be moved. --Izno (talk) 14:40, 19 October 2020 (UTC)

As it stands Category:WikiProject_Mathematics is rather dominated by the various lists of articles, so i support using a sub category, but it need to named it indicate project space. I would suggest Category:WikiProject Mathematics, list of mathematics articles.

There also seems to be some dead pages Wikipedia:WikiProject Mathematics/List of mathematics articles (A–C) has not been changed since 2013, so is presumably very out of date.--Salix alba (talk): 17:38, 19 October 2020 (UTC)

Okay fine Salix. But the comma looks strange so how about Category:WikiProject Mathematics list of mathematics articles or more succinctly Category:WikiProject Mathematics list of articles? The A-C page just transcludes the three separate pages A, B and C. Don't know why it's needed — Martin (MSGJ · talk) 18:22, 19 October 2020 (UTC)

Happy with Izno's suggestion also — Martin (MSGJ · talk) 18:23, 19 October 2020 (UTC)

I've marked the category with a temporary {{emptycat}} tag so it won't be continually tagged for CSD C1...please remove the tag when a decision has been made. Thanks. Liz ^{Read! Talk!} 14:37, 20 October 2020 (UTC)

Okay — Martin (MSGJ · talk) 17:16, 20 October 2020 (UTC)

Aren't lists such as List of mathematicians (A) mainspace lists? Why would they be categorized in Category:WikiProject Mathematics list of articles but not in any mainspace categories? Thanks. Starcheerspeaksnewslostwars^{Talk to me} 23:44, 23 October 2020 (UTC)

I think they should all be moved into project space because they are maintained by a bot. If a human makes a change, they will be likely be reverted by the bot in the next day. So I propose we move them all to Wikipedia:WikiProject Mathematics/List of mathematicians (A), etc. — Martin (MSGJ · talk) 18:51, 25 October 2020 (UTC)

Unless anyone has any comments on this, I will start moving them to project space shortly — Martin (MSGJ · talk) 13:12, 28 October 2020 (UTC)

Just to follow-up. These pages have all now been moved into project space and can be found in Category:WikiProject Mathematics list of mathematicians — Martin (MSGJ · talk) 22:42, 7 November 2020 (UTC)

US presidential election and edit warring at Benford's law

Not surprisingly, there has been considerable recent activity and edit warring at Benford's law with regard to its applicability to election fraud. The article would benefit from attention by knowledgeable editors. Paul August ☎ 10:05, 9 November 2020 (UTC)

Not surprisingly !! It seems the page has been protected, which should help. Frankly, that whole section relies much too heavily on primary sources. —JBL (talk) 13:05, 9 November 2020 (UTC)

I won't be touching that subsection of the page after what was added to it last week, since I now have a major COI with it (Walter Mebane is my PhD dissertation committee chair), but if anyone would like suggestions on sources please feel free to ping me into any relevant discussions. - Astrophobe (talk) 19:26, 9 November 2020 (UTC)

Punctuation

I found the first example below in an actual article. I changed it to the third.

Note also the second. It seems not universally realized that one of the differences between the system used here and full-fledged LaTeX is that a comma or period after a mathematical expression often gets misaligned or fails to match the font felicitously if it is outside rather than inside the math tags.

But I wonder whether there is someone who thinks either the first or the second form used here should be used. I keep seeing it and wondering whether people who do things like that when they're walking around bump into a telephone pole and suffer injuries. But that might not be the case if for some reason someone thinks it should be done that way.

First example:

$S(X,Y)={\begin{cases}1,&{\text{if }}Y<X\\{\tfrac {1}{2}},&{\text{if }}Y=X\\0,&{\text{if }}Y>X\end{cases}}$.

Second example:

$S(X,Y)={\begin{cases}1,&{\text{if }}Y<X\\{\tfrac {1}{2}},&{\text{if }}Y=X\\0,&{\text{if }}Y>X\end{cases}}.$

Third example:

$S(X,Y)={\begin{cases}1,&{\text{if }}Y<X,\\{\tfrac {1}{2}},&{\text{if }}Y=X,\\0,&{\text{if }}Y>X.\end{cases}}$

Michael Hardy (talk) 19:54, 8 November 2020 (UTC)

Surprisingly enough, I have just written the item Single brace in List of mathematical symbols. I have omitted the final period for being sure that nobody will think that this is a part of the notation. I have omitted also the commas at the end of the lines, because, without the final period they would be strange. I have also omitted the commas before the "if"s, but I am not sure whether there are needed or not. So, other editors opinions would also be useful for me.

In Michael's case, if final punctuation is required, it is clearly the third example that is the best. However, in many case, I would prefer to avoid punctuation at the end of lines, for example by having a colon that precedes the displayed formula ("we have thus:"). D.Lazard (talk) 21:06, 8 November 2020 (UTC)

I have changed my opinion: The third example is semantically incorrect: For the English syntax, a formula must be treated as a single entity. In these examples, the different cases belong to the same formula, as shown by the equal sign before the brace. Using end-line commas is thus similar to add a comma at the end of each row of a matrix. The absence of a right bracket does not make any semantic difference. So only the first two examples are semantically correct, and the second one provides a better rendering. However this looks strange, and omitting the period should be preferred, although, for purists, this may need to change the formulation for having a formula that is not a part of a complete sentence. This allows to apply MOS:LISTFORMAT: "A list item should not end with a full stop unless it consists of a complete sentence or is the end of a list that forms one." After all, for html semantics, a displayed formula is a list reduced to a single item. D.Lazard (talk) 13:41, 9 November 2020 (UTC)

It was my understanding that one places the punctuation mark at the end of the final item on the list, if one is treating the single brace expression as a single grammatical entity. That is, something like

$S(X,Y)={\begin{cases}1,&{\text{if }}Y<X\\{\tfrac {1}{2}},&{\text{if }}Y=X\\0,&{\text{if }}Y>X.\end{cases}}$

This is the main way I have seen it punctuated. It looks much less nasty than having the full stop in the middle of the expression vertically.Tazerenix (talk) 17:50, 9 November 2020 (UTC)

For what it's worth, I tend to agree. As someone who normally feels semantically giddy or syntactically bereft through a lack of expected punctuation, I much prefer this fourth example. It makes sense to apply English language punctuation to the entity as a whole. And to consider if less is more. Punctuation functions as a necessary disambiguator where text is linear; when the maths is 2D, it can be the spacing, row ends, etc, that helps with the parsing. I spent an embarrassingly long time trying to figure out if my screen was dirty when I first saw Examples 1 and 2. NeilOnWiki (talk) 18:34, 9 November 2020 (UTC)

I also agree with Tazerenix. —David Eppstein (talk) 19:01, 9 November 2020 (UTC)

Ok, Tazerenix's version make sense. D.Lazard (talk) 20:08, 9 November 2020 (UTC)

Listing proper units in a template

 You are invited to join the discussion at Template talk:Canadian election result § Template-protected edit request on 10 November 2020. Joeyconnick (talk) 06:58, 14 November 2020 (UTC)

Missing LaTeX macros: mathstrut, vphantom, vrule, and smash

Wikipedia's lobotomized version of LaTeX doesn't include mathstrut, vphantom, vrule, or smash. Does anyone know how to persuade it to make ${\sqrt {a^{2}+b^{2}}}$ and ${\sqrt {(a+r)^{2}+b^{2}}}$ have square roots the same size as each other? All the answers I can find on the web for this use one of these four missing macros. —David Eppstein (talk) 06:27, 13 November 2020 (UTC)

Calling it a "version of LaTeX" makes me uncomfortable. Genuine LaTeX does immensely more than typest mathematical notation. I wonder if those who master the software used here, and who see everyone call it "LaTeX", will think they've learned LaTeX and then go into shock when they encounter actual LaTeX and find they have no idea how to use it. E.g. what's this "\begin{document}" and "\usepackage" and "\setcounter{enumi}{6}" and "\input{ch6.tex}" and "\section*{blahblah}", etc? Michael Hardy (talk) 18:17, 16 November 2020 (UTC)

These two look the same size: ${\sqrt {(a^{2})+b^{2}}}$ and ${\sqrt {(a+r)^{2}+b^{2}}}$, but I suspect this may not be the answer you were looking for. --{{u|Mark viking}} {Talk} 23:02, 16 November 2020 (UTC)

I found a really really gross hack that appears to work: ${\sqrt {a^{2}+b^{2}{}_{\!}}}$ and ${\sqrt {(a+r)^{2}+b^{2}}}$. —David Eppstein (talk) 23:15, 16 November 2020 (UTC)

I was thinking along similar hack-y lines, like overset-ing a blank space on both: ${\sqrt {\overset {\,}{a^{2}+b^{2}}}}$ versus ${\sqrt {\overset {\,}{(a+r)^{2}+b^{2}}}}$. Yours seems more successful. XOR'easter (talk) 23:18, 16 November 2020 (UTC)

What is the use case for this? --JBL (talk) 00:22, 17 November 2020 (UTC)

Sometimes display=inline can help: ${\textstyle {\sqrt {a^{2}+b^{2}}}}$ and ${\textstyle {\sqrt {(a+r)^{2}+b^{2}}}}$ –jacobolus (t) 08:42, 22 September 2021 (UTC)

Covariance Matrix in Principle Component Analysis

Hello all,

In Principle Component Analysis, $X^{\top }{}X$ is stated to be proportional to the covariance matrix without proof or source. I believe it would be helpful to show how $X^{\top }{}X$ is related to the covariance matrix. Would adding the detail on how it is derived run afoul of WP:OR? -Mys_721tx (talk) 18:41, 17 November 2020 (UTC)

Scientific articles such as this have broad leeway in showing such details. See for example Wikipedia:CALC. So go ahead. That said, the proof maybe should not be included if it is long and pedagogical. See for example Wikipedia:TEXTBOOK. Mgnbar (talk) 18:59, 17 November 2020 (UTC)

The article on PCA seems a little light on in-line references as it is. Perhaps the first thing to do is find a textbook with an explanation that you particularly like and add a citation to it. And, as Mgnbar pointed out, Wikipedia articles aren't really the place for stepping through derivations one equation at a time; it's more important to say what a result is, what it implies, and what goes into proving it. There aren't hard-and-fast rules about this, however. XOR'easter (talk) 19:07, 17 November 2020 (UTC)

Thanks all! I cited Jolliffe 2002 and also fixed some other references in the same book. -Mys_721tx (talk) 19:57, 17 November 2020 (UTC)

RfC on the selectiveness of AMS fellowships

Hi all, I started a RfC Wikipedia talk:WikiProject Biography#RfC on AMS fellowship selectiveness to help determine if the American Mathematical Society fellowships count as selective enough to qualify mathematicians as notable under WP:NACADEMIC. If you know of consensus that has already been reached on this and believe I should withdraw the request, please let me know. I searched through the archives and could not find a past discussion on the topic, though I may have missed something. Thanks! Footlessmouse (talk) 23:38, 21 November 2020 (UTC)

Notation/formatting at Grassmannian

Anyone who enjoys arguing about mathematical notation and formatting is invited to weigh in here. --JBL (talk) 20:37, 22 November 2020 (UTC)

Cool commutative diagram builder app

Hey all,

I ran into this really cool commutative diagram building app today called quiver. And wow, it works really well. I'm surprised how easy it was to draw out a 3-commutative diagram using latex and their graphical editor. This is by far one of the most powerful tools (besides a latex compiler) for building diagrams. Unfortunately, it doesn't look like the app can export to SVG as of now, but it is on the list of github issues. Hopefully some other people here will find this tool useful :) . Wundzer (talk) 20:09, 25 November 2020 (UTC)

Dec 2020

Wikipedia talk:WikiProject Mathematics/Archive/2020/Dec