English

On profinite groups with automorphisms whose fixed points have countable Engel sinks

Group Theory 2020-06-11 v1

Abstract

An Engel sink of an element gg of a group GG is a set E(g){\mathscr E}(g) such that for every xGx\in G all sufficiently long commutators [...[[x,g],g],,g][...[[x,g],g],\dots ,g] belong to E(g){\mathscr E}(g). (Thus, gg is an Engel element precisely when we can choose E(g)={1}{\mathscr E}(g)=\{ 1\}.) It is proved that if a profinite group GG admits an elementary abelian group of automorphisms AA of coprime order q2q^2 for a prime qq such that for each aA{1}a\in A\setminus\{1\} every element of the centralizer CG(a)C_G(a) has a countable (or finite) Engel sink, then GG has a finite normal subgroup NN such that G/NG/N is locally nilpotent.

Keywords

Cite

@article{arxiv.2006.05959,
  title  = {On profinite groups with automorphisms whose fixed points have countable Engel sinks},
  author = {E. I. Khukhro and P. Shumyatsky},
  journal= {arXiv preprint arXiv:2006.05959},
  year   = {2020}
}

Comments

arXiv admin note: text overlap with arXiv:1908.11637, arXiv:2004.11680

R2 v1 2026-06-23T16:12:52.470Z