English

On finite groups containing an element whose Engel sink is small

Group Theory 2026-05-12 v1

Abstract

For an element gg of a group GG, a right Engel sink of gg is a subset of GG containing all sufficiently long commutators [...[[g,x],x],,x][...[[g ,x],x],\dots ,x] for all xGx\in G. A left Engel sink of gg is a subset of GG containing all sufficiently long commutators [...[[x,g],g],,g][...[[x ,g ],g ],\dots ,g] for all xGx\in G. Using the classification of finite simple groups we prove that if a finite group GG has an element gg such that G=[G,g]G=[G,g], then the order of GG is bounded in terms of a right Engel sink of gg, as well as in terms of a left Engel sink of gg. Earlier Guralnick and Tracey proved this in the case where gg is an involution without using the classification.

Keywords

Cite

@article{arxiv.2605.08607,
  title  = {On finite groups containing an element whose Engel sink is small},
  author = {Evgeny Khukhro and Pavel Shumyatsky},
  journal= {arXiv preprint arXiv:2605.08607},
  year   = {2026}
}
R2 v1 2026-07-01T12:59:23.069Z