{ "id": "1808.07317", "version": "v1", "published": "2018-08-22T11:26:35.000Z", "updated": "2018-08-22T11:26:35.000Z", "title": "Blocks with normal abelian defect and abelian p' inertial quotient", "authors": [ "David Benson", "Radha Kessar", "Markus Linckelmann" ], "categories": [ "math.RT", "math.GR" ], "abstract": "Let $k$ be an algebraically closed field of characteristic $p$, and let $\\mathcal{O}$ be either $k$ or its ring of Witt vectors $W(k)$. Let $G$ a finite group and $B$ a block of $\\mathcal{O}G$ with normal abelian defect group and abelian $p'$ inertial quotient. We show that $B$ is isomorphic to its second Frobenius twist. This is motivated by the fact that bounding Frobenius numbers is one of the key steps towards Donovan's conjecture. For $\\mathcal{O}=k$, we give an explicit description of the basic algebra of $B$ as a quiver with relations. It is a quantised version of the group algebra of the semidirect product $P\\rtimes L$.", "revisions": [ { "version": "v1", "updated": "2018-08-22T11:26:35.000Z" } ], "analyses": { "subjects": [ "20C20", "20J06" ], "keywords": [ "inertial quotient", "normal abelian defect group", "second frobenius twist", "witt vectors", "semidirect product" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }