{ "id": "2003.06384", "version": "v1", "published": "2020-03-13T17:07:25.000Z", "updated": "2020-03-13T17:07:25.000Z", "title": "An approach to Quillen's conjecture via centralizers of simple groups", "authors": [ "Kevin Ivan Piterman" ], "comment": "14 pages", "categories": [ "math.GR", "math.AT" ], "abstract": "We show that, for any given subgroup $H$ of a finite group $G$, the Quillen poset $\\mathcal{A}_p(G)$ of nontrivial elementary abelian $p$-subgroups, is obtained from $\\mathcal{A}_p(H)$ by attaching elements via their centralizers in $H$. We use this idea to study Quillen's conjecture, which asserts that if $\\mathcal{A}_p(G)$ is contractible then $G$ has a nontrivial normal $p$-subgroup. We prove that the original conjecture is equivalent to the $\\mathbb{Z}$-acyclic version of the conjecture (obtained by replacing contractible by $\\mathbb{Z}$-acyclic). We also work with the $\\mathbb{Q}$-acyclic (strong) version of the conjecture, reducing its study to extensions of direct products of simple groups of order divisible by $p$ and $p$-rank at least $2$. This allows to extend results of Aschbacher-Smith and to establish the strong conjecture for groups of $p$-rank at most $4$.", "revisions": [ { "version": "v1", "updated": "2020-03-13T17:07:25.000Z" } ], "analyses": { "subjects": [ "20J05", "20D05", "20D25", "20D30", "05E18", "06A11" ], "keywords": [ "simple groups", "centralizers", "nontrivial elementary abelian", "study quillens conjecture", "finite group" ], "note": { "typesetting": "TeX", "pages": 14, "language": "en", "license": "arXiv", "status": "editable" } } }