Coprime commutators in profinite groups
Group Theory
2026-04-08 v2
Abstract
By a coprime commutator in a profinite group we mean any element of the form , where and . It is well-known that the subgroup generated by the coprime commutators of is precisely the pronilpotent residual . There are several recent works showing that finiteness conditions on the set of coprime commutators have strong impact on the properties of and, more generally, on the structure of . In this paper we show that if the set of coprime commutators of a profinite group is covered by countably many procyclic subgroups, then is finite-by-procyclic. In particular, it follows that is finite-by-pronilpotent-by-abelian.
Cite
@article{arxiv.2510.03754,
title = {Coprime commutators in profinite groups},
author = {Cristina Acciarri and Pavel Shumyatsky},
journal= {arXiv preprint arXiv:2510.03754},
year = {2026}
}
Comments
24 pages, revised version, to appear in Revista Matem\'atica Complutense