{ "id": "2307.09868", "version": "v1", "published": "2023-07-19T09:57:25.000Z", "updated": "2023-07-19T09:57:25.000Z", "title": "On the commuting probability of $π$-elements in finite groups", "authors": [ "Juan Martínez" ], "comment": "16 pages", "categories": [ "math.GR" ], "abstract": "Let $G$ be a finite group and let $\\pi$ be a set of primes. In this work, we prove that $G$ possesses a normal and abelian Hall $\\pi$-subgroup if and only if the probability that two random $\\pi$-elements of $G$ commute is larger than $\\frac{p^2+p-1}{p^3}$, where $p$ is the smallest prime in $\\pi$. We also prove that if $x$ is a $\\pi$-element not lying in $O_{\\pi}(G)$, then the proportion of $\\pi$-elements commuting with $x$ is at most $1/p$, where $p$ is the smallest prime in $\\pi$.", "revisions": [ { "version": "v1", "updated": "2023-07-19T09:57:25.000Z" } ], "analyses": { "subjects": [ "20D20" ], "keywords": [ "finite group", "commuting probability", "smallest prime", "abelian hall", "proportion" ], "note": { "typesetting": "TeX", "pages": 16, "language": "en", "license": "arXiv", "status": "editable" } } }