{ "id": "0906.1790", "version": "v2", "published": "2009-06-09T17:37:00.000Z", "updated": "2009-06-10T14:53:46.000Z", "title": "Counting p'-characters in finite reductive groups", "authors": [ "Olivier Brunat" ], "doi": "10.1112/jlms/jdq001", "categories": [ "math.RT" ], "abstract": "This article is concerned with the relative McKay conjecture for finite reductive groups. Let G be a connected reductive group defined over the finite field F_q of characteristic p>0 with corresponding Frobenius map F. We prove that if the F-coinvariants of the component group of the center of G has prime order and if p is a good prime for G, then the relative McKay conjecture holds for G at the prime p. In particular, this conjecture is true for G^F in defining characteristic for G a simple and simply-connected group of type B_n, C_n, E_6 and E_7. Our main tools are the theory of Gelfand-Graev characters for connected reductive groups with disconnected center developed by Digne-Lehrer-Michel and the theory of cuspidal Levi subgroups. We also explicitly compute the number of semisimple classes of G^F for any simple algebraic group G.", "revisions": [ { "version": "v2", "updated": "2009-06-10T14:53:46.000Z" } ], "analyses": { "subjects": [ "20C15", "20C33" ], "keywords": [ "finite reductive groups", "connected reductive group", "simple algebraic group", "cuspidal levi subgroups", "relative mckay conjecture holds" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2009arXiv0906.1790B" } } }