{ "id": "1610.02079", "version": "v1", "published": "2016-10-06T21:44:54.000Z", "updated": "2016-10-06T21:44:54.000Z", "title": "Almost Engel compact groups", "authors": [ "E. I. Khukhro", "P. Shumyatsky" ], "comment": "arXiv admin note: substantial text overlap with arXiv:1512.06097", "categories": [ "math.GR" ], "abstract": "We say that a group $G$ is almost Engel if for every $g\\in G$ there is a finite set ${\\mathscr E}(g)$ such that for every $x\\in G$ all sufficiently long commutators $[...[[x,g],g],\\dots ,g]$ belong to ${\\mathscr E}(g)$, that is, for every $x\\in G$ there is a positive integer $n(x,g)$ such that $[...[[x,g],g],\\dots ,g]\\in {\\mathscr E}(g)$ if $g$ is repeated at least $n(x,g)$ times. (Thus, Engel groups are precisely the almost Engel groups for which we can choose ${\\mathscr E}(g)=\\{ 1\\}$ for all $g\\in G$.) We prove that if a compact (Hausdorff) group $G$ is almost Engel, then $G$ has a finite normal subgroup $N$ such that $G/N$ is locally nilpotent. If in addition there is a unform bound $|{\\mathscr E}(g)|\\leq m$ 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.", "revisions": [ { "version": "v1", "updated": "2016-10-06T21:44:54.000Z" } ], "analyses": { "keywords": [ "engel compact groups", "engel groups", "locally nilpotent", "finite normal subgroup", "engel profinite groups" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }