{ "id": "0804.3781", "version": "v3", "published": "2008-04-23T19:00:05.000Z", "updated": "2008-12-16T21:52:24.000Z", "title": "Hecke group algebras as quotients of affine Hecke algebras at level 0", "authors": [ "Florent Hivert", "Anne Schilling", "Nicolas M. ThiƩry" ], "comment": "21 pages; 4 figures v2: improved presentation, 23 pages v3: final proofreading, to appear in Journal of Combinatorial Theory Series A", "journal": "Journal of Combinatorial Theory, Series A 116 (2009) 844-863", "doi": "10.1016/j.jcta.2008.11.010", "categories": [ "math.RT", "math.CO" ], "abstract": "The Hecke group algebra $HW_0$ of a finite Coxeter group $W_0$, as introduced by the first and last author, is obtained from $W_0$ by gluing appropriately its 0-Hecke algebra and its group algebra. In this paper, we give an equivalent alternative construction in the case when $W_0$ is the classical Weyl group associated to an affine Weyl group $W$. Namely, we prove that, for $q$ not a root of unity, $HW_0$ is the natural quotient of the affine Hecke algebra through its level 0 representation. We further show that the level 0 representation is a calibrated principal series representation for a suitable choice of character, so that the quotient factors (non trivially) through the principal central specialization. This explains in particular the similarities between the representation theory of the classical 0-Hecke algebra and that of the affine Hecke algebra at this specialization.", "revisions": [ { "version": "v3", "updated": "2008-12-16T21:52:24.000Z" } ], "analyses": { "subjects": [ "20C08", "05E15" ], "keywords": [ "affine hecke algebra", "hecke group algebra", "affine weyl group", "finite coxeter group", "calibrated principal series representation" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 21, "language": "en", "license": "arXiv", "status": "editable", "inspire": 800373, "adsabs": "2008arXiv0804.3781H" } } }