{ "id": "2505.06130", "version": "v1", "published": "2025-05-09T15:36:17.000Z", "updated": "2025-05-09T15:36:17.000Z", "title": "Powers of commutators in infinite groups", "authors": [ "Daan Heus" ], "comment": "17 pages; 1 figure; this paper is based on my bachelor's and master's theses, written at Leiden University under the supervision of Hendrik Lenstra", "categories": [ "math.GR" ], "abstract": "Given elements $x,u,z$ in a finite group $G$ such that $z$ is the commutator of $x$ and $u$, and the orders of $x$ and $z$ divide respectively integers $k,m \\geq 2$, and given an integer $r$ that is coprime to $k$ and $m$, there exists $w \\in G$ such that the commutator of $x^r$ and $w$ is conjugate to $z^r$. If instead we are given elements $x,y,z \\in G$ such that $xy = z$, whose respective orders divide integers $k,l,m \\geq 2$, and are given an integer $r$ that is coprime to $k,l$ and $m$, then there exist $x'$, $y'$ and $z'$ conjugate to respectively $x^r$, $y^r$ and $z^r$ such that $x'y' = z'$. In this paper we completely answer the natural question for which values of $k,l,m,r$ every group has these properties. The proof uses combinatorial group theory and properties of the projective special linear group $\\mathrm{PSL}_2(\\mathbb{R})$.", "revisions": [ { "version": "v1", "updated": "2025-05-09T15:36:17.000Z" } ], "analyses": { "subjects": [ "20F12", "20E45" ], "keywords": [ "infinite groups", "commutator", "projective special linear group", "respective orders divide integers", "combinatorial group theory" ], "note": { "typesetting": "TeX", "pages": 17, "language": "en", "license": "arXiv", "status": "editable" } } }