{ "id": "1807.06452", "version": "v1", "published": "2018-07-14T13:21:24.000Z", "updated": "2018-07-14T13:21:24.000Z", "title": "Compact groups all elements of which are almost right Engel", "authors": [ "E. I. Khukhro", "P. Shumyatsky" ], "comment": "arXiv admin note: substantial text overlap with arXiv:1610.02079, arXiv:1512.06097", "categories": [ "math.GR" ], "abstract": "We say that an element $g$ of a group $G$ is almost right Engel if there is a finite set ${\\mathscr R}(g)$ such that for every $x\\in G$ all sufficiently long commutators $[...[[g,x],x],\\dots ,x]$ belong to ${\\mathscr R}(g)$, that is, for every $x\\in G$ there is a positive integer $n(x,g)$ such that $[...[[g,x],x],\\dots ,x]\\in {\\mathscr R}(g)$ if $x$ is repeated at least $n(x,g)$ times. Thus, $g$ is a right Engel element precisely when we can choose ${\\mathscr R}(g)=\\{ 1\\}$. We prove that if all elements of a compact (Hausdorff) group $G$ are almost right Engel, then $G$ has a finite normal subgroup $N$ such that $G/N$ is locally nilpotent. If in addition there is a uniform bound $|{\\mathscr R}(g)|\\leq m$ for the orders of the corresponding sets, then the subgroup $N$ can be chosen of order bounded in terms of $m$. 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.", "revisions": [ { "version": "v1", "updated": "2018-07-14T13:21:24.000Z" } ], "analyses": { "subjects": [ "20D25", "20E18", "20F45" ], "keywords": [ "compact groups", "engel profinite groups", "right engel element", "locally nilpotent", "finite normal subgroup" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }