Talk:Power automorphism

"If the group is abelian, any powering index works." This statement must be restricted to finite groups, or be otherwise refined. In the group of all integers (with addition) only powering index 1 and -1 work. In the group that consists of all rationals whose denominator is a power of a prime $p$ (with addition) every nonzero integer is a valid powering index.

Maybe it should also made clearer that for finite abelian groups the "relatively prime" requirement still holds, disqualifying the word "any". I am not entirely sure if this is also necessary for infinite groups: in the Pruefer p-group the p-th power map seems to be a valid automorphism.

Leen Droogendijk (talk) 10:35, 13 February 2018 (UTC)