{ "id": "1305.1684", "version": "v4", "published": "2013-05-08T00:07:34.000Z", "updated": "2015-09-17T22:26:03.000Z", "title": "Parity sheaves on the affine Grassmannian and the Mirković-Vilonen conjecture", "authors": [ "Pramod N. Achar", "Laura Rider" ], "comment": "27 pages. v4: added details to Section 2 and an appendix on sheaf functors on non-locally compact spaces", "categories": [ "math.RT" ], "abstract": "We prove the Mirkovi\\'c-Vilonen conjecture: the integral local intersection cohomology groups of spherical Schubert varieties on the affine Grassmannian have no p-torsion, as long as p is outside a certain small and explicitly given set of prime numbers. (Juteau has exhibited counterexamples when p is a bad prime.) The main idea is to convert this topological question into an algebraic question about perverse-coherent sheaves on the dual nilpotent cone using the Juteau-Mautner-Williamson theory of parity sheaves.", "revisions": [ { "version": "v3", "updated": "2014-07-03T11:44:42.000Z", "comment": "22 pages. v3: corrected a mistake in Section 5", "journal": null, "doi": null }, { "version": "v4", "updated": "2015-09-17T22:26:03.000Z" } ], "analyses": { "subjects": [ "22E57", "14F05" ], "keywords": [ "parity sheaves", "affine grassmannian", "mirković-vilonen conjecture", "integral local intersection cohomology groups", "dual nilpotent cone" ], "note": { "typesetting": "TeX", "pages": 27, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1305.1684A" } } }