{ "id": "2405.10726", "version": "v1", "published": "2024-05-17T12:17:45.000Z", "updated": "2024-05-17T12:17:45.000Z", "title": "$τ$-Tilting finiteness of group algebras over generalized symmetric groups", "authors": [ "Naoya Hiramae" ], "comment": "15 pages. arXiv admin note: text overlap with arXiv:2405.10021", "categories": [ "math.RT", "math.GR", "math.RA" ], "abstract": "In this paper, we show that weakly symmetric $\\tau$-tilting finite algebras have positive definite Cartan matrices, which implies that we can prove $\\tau$-tilting infiniteness of weakly symmetric algebras by calculating their Cartan matrices. Similarly, we obtain the condition on Cartan matrices that selfinjective algebras are $\\tau$-tilting infinite. By applying this result, we show that a group algebra of $(\\mathbb{Z}/p^l\\mathbb{Z})^n\\rtimes H$ is $\\tau$-tilting infinite when $p^l\\geq n$ and $\\#\\mathrm{IBr}\\,H\\geq\\min\\{p,3\\}$, where $p>0$ is the characteristic of the ground field, $H$ is a subgroup of the symmetric group $\\mathfrak{S}_n$ of degree $n$, the action of $H$ permutes the entries of $(\\mathbb{Z}/p^l\\mathbb{Z})^n$, and $\\mathrm{IBr}\\,H$ denotes the set of irreducible $p$-Brauer characters of $H$. Moreover, we show that under the assumption that $p^l\\geq n$ and $H$ is a $p'$-subgroup of $\\mathfrak{S}_n$, $\\tau$-tilting finiteness of a group algebra of a group $(\\mathbb{Z}/p^l\\mathbb{Z})^n\\rtimes H$ is determined by its $p$-hyperfocal subgroup.", "revisions": [ { "version": "v1", "updated": "2024-05-17T12:17:45.000Z" } ], "analyses": { "subjects": [ "16G10", "20C20" ], "keywords": [ "group algebra", "generalized symmetric groups", "tilting finiteness", "weakly symmetric", "tilting infinite" ], "note": { "typesetting": "TeX", "pages": 15, "language": "en", "license": "arXiv", "status": "editable" } } }