{ "id": "2008.02433", "version": "v1", "published": "2020-08-06T02:34:31.000Z", "updated": "2020-08-06T02:34:31.000Z", "title": "Groups in which the co-degrees of the irreducible characters are distinct", "authors": [ "Mahdi Ebrahimi" ], "categories": [ "math.GR" ], "abstract": "Let $G$ be a finite group and let $\\rm{Irr}(G)$ be the set of all irreducible complex characters of $G$. For a character $\\chi \\in \\rm{Irr}(G)$, the number $\\rm{cod}(\\chi):=|G:\\rm{ker}\\chi|/\\chi(1)$ is called the co-degree of $\\chi$. The set of co-degrees of all irreducible characters of $G$ is denoted by $\\rm{cod}(G)$. In this paper, we show that for a non-trivial finite group $G$, $|\\rm{Irr}(G)|=|\\rm{cod}(G)|$ if and only if $G$ is isomorphic to the cyclic group $\\mathbb{Z}_2$ or the symmetric group $S_3$.", "revisions": [ { "version": "v1", "updated": "2020-08-06T02:34:31.000Z" } ], "analyses": { "subjects": [ "20C15", "05C25" ], "keywords": [ "irreducible characters", "non-trivial finite group", "symmetric group", "irreducible complex characters", "cyclic group" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }