English

Compact groups all elements of which are almost right Engel

Group Theory 2018-07-18 v1

Abstract

We say that an element gg of a group GG is almost right Engel if there is a finite set R(g){\mathscr R}(g) such that for every xGx\in G all sufficiently long commutators [...[[g,x],x],,x][...[[g,x],x],\dots ,x] belong to R(g){\mathscr R}(g), that is, for every xGx\in G there is a positive integer n(x,g)n(x,g) such that [...[[g,x],x],,x]R(g)[...[[g,x],x],\dots ,x]\in {\mathscr R}(g) if xx is repeated at least n(x,g)n(x,g) times. Thus, gg is a right Engel element precisely when we can choose R(g)={1}{\mathscr R}(g)=\{ 1\}. We prove that if all elements of a compact (Hausdorff) group GG are almost right Engel, then GG has a finite normal subgroup NN such that G/NG/N is locally nilpotent. If in addition there is a uniform bound R(g)m|{\mathscr R}(g)|\leq m for the orders of the corresponding sets, then the subgroup NN can be chosen of order bounded in terms of mm. The proofs use the Wilson--Zelmanov theorem saying that Engel profinite groups are locally nilpotent and previous results of the authors about compact groups all elements of which are almost left Engel.

Keywords

Cite

@article{arxiv.1807.06452,
  title  = {Compact groups all elements of which are almost right Engel},
  author = {E. I. Khukhro and P. Shumyatsky},
  journal= {arXiv preprint arXiv:1807.06452},
  year   = {2018}
}

Comments

arXiv admin note: substantial text overlap with arXiv:1610.02079, arXiv:1512.06097

R2 v1 2026-06-23T03:04:23.924Z