{ "id": "0809.3046", "version": "v3", "published": "2008-09-18T01:17:17.000Z", "updated": "2009-03-25T19:00:16.000Z", "title": "Groups with the same cohomology as their pro-$p$ completions", "authors": [ "Karl Lorensen" ], "comment": "The revisions in the second version pertain to the exposition: the proof of Prop. 1.1, in particular, now includes more details. The third version includes a proof that right-angled Artin groups are residually $p$-finite for every prime $p$", "journal": "J. Pure Appl. Algebra 214 (2010), 6-14", "categories": [ "math.GR", "math.KT" ], "abstract": "For any prime $p$ and group $G$, denote the pro-$p$ completion of $G$ by $\\hat{G}^p$. Let $\\mathcal{C}$ be the class of all groups $G$ such that, for each natural number $n$ and prime number $p$, $H^n(\\hat{G^p},\\mathbb Z/p)\\cong H^n(G, \\mathbb Z/p)$, where $\\mathbb Z/p$ is viewed as a discrete, trivial $\\hat{G}^p$-module. In this article we identify certain kinds of groups that lie in $\\mathcal{C}$. In particular, we show that right-angled Artin groups are in $\\mathcal{C}$ and that this class also contains some special types of free products with amalgamation.", "revisions": [ { "version": "v3", "updated": "2009-03-25T19:00:16.000Z" } ], "analyses": { "subjects": [ "20E18", "20E06", "20F36" ], "keywords": [ "completion", "cohomology", "natural number", "free products", "right-angled artin groups" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2008arXiv0809.3046L" } } }