{ "id": "2309.14804", "version": "v1", "published": "2023-09-26T10:00:15.000Z", "updated": "2023-09-26T10:00:15.000Z", "title": "Generic direct summands of tensor productsfor simple algebraic groups and quantum groups", "authors": [ "Jonathan Gruber" ], "comment": "24 pages, 1 figure, comments welcome", "categories": [ "math.RT", "math.QA" ], "abstract": "Let $\\mathbf{G}$ be either a simple linear algebraic group over an algebraically closed field of positive characteristic or a quantum group at a root of unity. We define new classes of indecomposable $\\mathbf{G}$-modules, which we call generic direct summands of tensor products because they appear generically in Krull-Schmidt decompositions of tensor products of simple $\\mathbf{G}$-modules and of Weyl modules. We establish a Steinberg-Lusztig tensor product theorem for generic direct summands of tensor products of simple $\\mathbf{G}$-modules and provide examples of generic direct summands for $\\mathbf{G}$ of type $\\mathrm{A}_1$ and $\\mathrm{A}_2$.", "revisions": [ { "version": "v1", "updated": "2023-09-26T10:00:15.000Z" } ], "analyses": { "subjects": [ "20G05", "20G42", "17B55", "17B10" ], "keywords": [ "generic direct summands", "tensor productsfor simple algebraic groups", "quantum group", "simple linear algebraic group" ], "note": { "typesetting": "TeX", "pages": 24, "language": "en", "license": "arXiv", "status": "editable" } } }