Talk:Mathematical descriptions of the electromagnetic field

Potential formulation - number of quantities

"In the potential formulation, there are only four quantities, the electric potential and the three components of the scalar potential."

is this a mistake? should it say "and the three components of the magnetic vector potential" ?

thanks

QED

The section Extension to quantum electrodynamics needs expansion, including what $\psi ^{+}$ and $\psi ^{-}$ are. F = q(E+v×B) ⇄ ∑_ic_i 16:27, 29 March 2012 (UTC)

math template

I don't understand the point of the math template for the inline text - it simply disrupts the font appearance between arial and whatever the math template font is. For things like:

"The most common description of the electromagnetic field to use two three-dimensional vector fields called the electric field and the magnetic field. These vector fields each have a value defined at every point of space and time and are thus often regarded as functions of the space and time coordinates. As such, they are often written as E(x, y, z, t) (electric field) and B(x, y, z, t) (magnetic field)."

or:

"where ρ is the charge density, which can (and often does) depend on time and position, ε₀ is the electric constant, μ₀ is the magnetic constant, and J is the current per unit area, also a function of time and position. The units used above are the standard SI units."

we can just write:

"The most common description of the electromagnetic field to use two three-dimensional vector fields called the electric field and the magnetic field. These vector fields each have a value defined at every point of space and time and are thus often regarded as functions of the space and time coordinates. As such, they are often written as E(x, y, z, t) (electric field) and B(x, y, z, t) (magnetic field)."

or:

"where ρ is the charge density, which can (and often does) depend on time and position, ε₀ is the electric constant, μ₀ is the magnetic constant, and J is the current per unit area, also a function of time and position. The units used above are the standard SI units."

which is far cleaner and less to write with no loss of continuity... For this article I will change math to hmtl (inline symbols, not displayed formulae). F = q(E+v×B) ⇄ ∑_ic_i 20:53, 17 May 2012 (UTC)

I think this is one of those instances where preferences differ (I've seen people making changes in both directions). People who have default browser serif and sans-serif fonts that work well together will often prefer the inline {{math}}, because then there is no clash and there is less inconsistency between the inline and the <math> displays, which can be jarring. In time, presumably MathJax will replace the PNG math display, and then we'll have a whole new bunch of complaints and preferences. For now, the simplest is to stick to making the style consistent within the article. — Quondum^☏ 14:24, 18 May 2012 (UTC)

Agreed. F = q(E+v×B) ⇄ ∑_ic_i 14:29, 18 May 2012 (UTC)

Merge Classical electromagnetism and special relativity to here?

See here. Opinions? (By no means insert Covariant formulation of classical electromagnetism into this article). F = q(E+v×B) ⇄ ∑_ic_i 15:15, 19 May 2012 (UTC)

Merge banners to be removed, no favour, one opposition. F = q(E+v×B) ⇄ ∑_ic_i 14:50, 21 May 2012 (UTC)

Removal of content

I will remove the relativistic material from this article to that one - see here. F = q(E+v×B) ⇄ ∑_ic_i 14:50, 21 May 2012 (UTC)

Also the entire section on covariant tensor forms - see the same link. F = q(E+v×B) ⇄ ∑_ic_i 12:44, 22 May 2012 (UTC)

Source equation in covariant derivative

Is it right to say

$$\mathrm {d} {\star \mathbf {F} }={\frac {1}{6}}{F^{\alpha \beta }}_{;\alpha }{\sqrt {-g}}\,\varepsilon _{\beta \gamma \delta \eta }\mathrm {d} x^{\gamma }\wedge \mathrm {d} x^{\delta }\wedge \mathrm {d} x^{\eta }=\mathbf {J} ,$$

or

$$\mathrm {d} {\star \mathbf {F} }={\frac {1}{6}}{F^{\alpha \beta }}_{;\alpha }{\sqrt {-g}}\,\varepsilon _{\beta \gamma \delta \alpha }\mathrm {d} x^{\gamma }\wedge \mathrm {d} x^{\delta }\wedge \mathrm {d} x^{\alpha }=\mathbf {J} ,$$

I think because our dimension is composed of four spacetime, we should use four coordinate indices. But I'm still not sure about converting, especially for the order of exterior product. Watsondoe (talk) 23:03, 3 February 2024 (UTC)