{ "id": "1604.07333", "version": "v1", "published": "2016-04-25T17:12:49.000Z", "updated": "2016-04-25T17:12:49.000Z", "title": "A filtration on rings of representations of non-Archimedean $GL_n$", "authors": [ "Maxim Gurevich" ], "comment": "11 pages", "categories": [ "math.RT" ], "abstract": "Let $F$ be a $p$-adic field. Let $\\mathcal{R}$ be the Grothendieck ring of complex smooth finite-length representations of the groups $\\{GL_n(F)\\}_{n=0}^\\infty$ taken together, with multiplication defined in the sense of parabolic induction. We introduce a width invariant for elements of $\\mathcal{R}$ and show that it gives an increasing filtration on the ring. Irreducible representations of width $1$ are precisely those known as ladder representations. We thus obtain a necessary condition on irreducible factors of a product of two ladder representations. For such a product we further establish a multiplicity-one phenomenon, which was previously observed in special cases.", "revisions": [ { "version": "v1", "updated": "2016-04-25T17:12:49.000Z" } ], "analyses": { "subjects": [ "20G25", "22E50" ], "keywords": [ "filtration", "non-archimedean", "complex smooth finite-length representations", "ladder representations", "necessary condition" ], "note": { "typesetting": "TeX", "pages": 11, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2016arXiv160407333G" } } }