{ "id": "2101.06851", "version": "v1", "published": "2021-01-18T02:32:41.000Z", "updated": "2021-01-18T02:32:41.000Z", "title": "Subregular $J$-rings of Coxeter systems via quiver path algebras", "authors": [ "Ivan Dimitrov", "Charles Paquette", "David Wehlau", "Tianyuan Xu" ], "comment": "49 pages, 7 figures", "categories": [ "math.RT", "math.GR", "math.RA" ], "abstract": "We study the subregular $J$-ring $J_C$ of a Coxeter system $(W,S)$, a subring of Lusztig's $J$-ring. We prove that $J_C$ is isomorphic to a quotient of the path algebra of the double quiver of $(W,S)$ by a suitable ideal that we associate to a family of Chebyshev polynomials. As applications, we use quiver representations to study the category mod-$A_K$ of finite dimensional right modules of the algebra $A_K=K\\otimes_\\Z J_C$ over an algebraically closed field $K$ of characteristic zero. Our results include classifications of Coxeter systems for which mod-$A_K$ is semisimple, has finitely many simple modules up to isomorphism, or has a bound on the dimensions of simple modules. Incidentally, we show that every group algebra of a free product of finite cyclic groups is Morita equivalent to the algebra $A_K$ for a suitable Coxeter system; this allows us to specialize the classifications to the module categories of such group algebras.", "revisions": [ { "version": "v1", "updated": "2021-01-18T02:32:41.000Z" } ], "analyses": { "subjects": [ "20C08", "16G20", "16D60", "20C07", "20E06" ], "keywords": [ "quiver path algebras", "subregular", "group algebra", "simple modules", "finite dimensional right modules" ], "note": { "typesetting": "TeX", "pages": 49, "language": "en", "license": "arXiv", "status": "editable" } } }