Profinite groups with complemented closed subgroups
Group Theory
2025-07-29 v1
Abstract
A group is said to be a -group if every subgroup has a permutable complement, i.e. if there exists a subgroup of such that and . In this paper, we study the profinite counterpart of this concept. We say that a profinite group is profinite- if every closed subgroup admits a closed permutable complement. We first give some equivalent variants of this condition and then we determine the structure of profinite- groups: they are the semidirect products of two closed subgroups and that are cartesian products of cyclic groups of prime order, and with every normal in . Finally, we show that a profinite- group is a -group if and only if it is torsion and .
Cite
@article{arxiv.2507.20791,
title = {Profinite groups with complemented closed subgroups},
author = {Gustavo A. Fernández-Alcober and Giulia Sabatino},
journal= {arXiv preprint arXiv:2507.20791},
year = {2025}
}
Comments
10 pages