{ "id": "1311.2983", "version": "v2", "published": "2013-11-12T23:54:02.000Z", "updated": "2014-03-31T22:47:51.000Z", "title": "A group sum inequality and its application to power graphs", "authors": [ "Brian Curtin", "Gholam Reza Pourgholi" ], "doi": "10.1017/S0004972714000434", "categories": [ "math.GR", "math.CO" ], "abstract": "Let $G$ be a finite group of order $n$, and let $C_n$ be the cyclic group of order $n$. We show that $\\sum_{g \\in C_n} \\phi(\\mathrm{o}(g))\\geq \\sum_{g \\in G} \\phi(\\mathrm{o}(g))$, with equality if and only if $G$ is isomorphic to $C_n$. As an application, we show that among all finite groups of a given order, the cyclic group of that order has the maximum number of undirected edges in its directed power graph.", "revisions": [ { "version": "v2", "updated": "2014-03-31T22:47:51.000Z" } ], "analyses": { "subjects": [ "05C25", "20F99" ], "keywords": [ "group sum inequality", "application", "finite group", "cyclic group", "maximum number" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1311.2983C" } } }