{ "id": "2108.02021", "version": "v1", "published": "2021-08-04T12:45:01.000Z", "updated": "2021-08-04T12:45:01.000Z", "title": "Probabilistically nilpotent groups of class two", "authors": [ "Sean Eberhard", "Pavel Shumyatsky" ], "comment": "20 pages", "categories": [ "math.GR" ], "abstract": "For $G$ a finite group, let $d_2(G)$ denote the proportion of triples $(x, y, z) \\in G^3$ such that $[x, y, z] = 1$. We determine the structure of finite groups $G$ such that $d_2(G)$ is bounded away from zero: if $d_2(G) \\geq \\epsilon > 0$, $G$ has a class-4 nilpotent normal subgroup $H$ such that $[G : H] $ and $|\\gamma_4(H)|$ are both bounded in terms of $\\epsilon$. We also show that if $G$ is an infinite group whose commutators have boundedly many conjugates, or indeed if $G$ satisfies a certain more general commutator covering condition, then $G$ is finite-by-class-3-nilpotent-by-finite.", "revisions": [ { "version": "v1", "updated": "2021-08-04T12:45:01.000Z" } ], "analyses": { "subjects": [ "20F24", "20F18", "20F69", "20P05" ], "keywords": [ "probabilistically nilpotent groups", "general commutator covering condition", "nilpotent normal subgroup", "infinite group", "conjugates" ], "note": { "typesetting": "TeX", "pages": 20, "language": "en", "license": "arXiv", "status": "editable" } } }