{ "id": "1707.06889", "version": "v1", "published": "2017-07-20T10:01:20.000Z", "updated": "2017-07-20T10:01:20.000Z", "title": "Profinite groups and centralizers of coprime automorphisms whose elements are Engel", "authors": [ "Cristina Acciarri", "Danilo Sanção da Silveira" ], "comment": "arXiv admin note: text overlap with arXiv:1702.02899, arXiv:1602.01661, arXiv:1108.0698", "categories": [ "math.GR" ], "abstract": "Let $q$ be a prime, $n$ a positive integer and $A$ an elementary abelian group of order $q^r$ with $r\\geq2$ acting on a finite $q'$-group $G$. The following results are proved. We show that if all elements in $\\gamma_{r-1}(C_G(a))$ are $n$-Engel in $G$ for any $a\\in A^\\#$, then $\\gamma_{r-1}(G)$ is $k$-Engel for some $\\{n,q,r\\}$-bounded number $k$, and if, for some integer $d$ such that $2^d\\leq r-1$, all elements in the $d$th derived group of $C_G(a)$ are $n$-Engel in $G$ for any $a\\in A^\\#$, then the $d$th derived group $G^{(d)}$ is $k$-Engel for some $\\{n,q,r\\}$-bounded number $k$. Assuming $r\\geq 3$ we prove that if all elements in $\\gamma_{r-2}(C_G(a))$ are $n$-Engel in $C_G(a)$ for any $a\\in A^\\#$, then $\\gamma_{r-2}(G)$ is $k$-Engel for some $\\{n,q,r\\}$-bounded number $k$, and if, for some integer $d$ such that $2^d\\leq r-2$, all elements in the $d$th derived group of $C_G(a)$ are $n$-Engel in $C_G(a)$ for any $a\\in A^\\#,$ then the $d$th derived group $G^{(d)}$ is $k$-Engel for some $\\{n,q,r\\}$-bounded number $k$. Analogue (non-quantitative) results for profinite groups are also obtained.", "revisions": [ { "version": "v1", "updated": "2017-07-20T10:01:20.000Z" } ], "analyses": { "subjects": [ "20D45", "20E18", "20F40", "20F45" ], "keywords": [ "th derived group", "profinite groups", "coprime automorphisms", "bounded number", "centralizers" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }