{ "id": "1102.2820", "version": "v1", "published": "2011-02-14T16:27:27.000Z", "updated": "2011-02-14T16:27:27.000Z", "title": "Koszul duality and semisimplicity of Frobenius", "authors": [ "Pramod N. Achar", "Simon Riche" ], "comment": "76 pages", "categories": [ "math.RT", "math.AG" ], "abstract": "A fundamental result of Beilinson-Ginzburg-Soergel states that on flag varieties and related spaces, a certain modified version of the category of l-adic perverse sheaves exhibits a phenomenon known as Koszul duality. The modification essentially consists of discarding objects whose stalks carry a nonsemisimple action of Frobenius. In this paper, we prove that a number of common sheaf functors (various pull-backs and push-forwards) induce corresponding functors on the modified category or its triangulated analogue. In particular, we show that these functors preserve semisimplicity of the Frobenius action.", "revisions": [ { "version": "v1", "updated": "2011-02-14T16:27:27.000Z" } ], "analyses": { "keywords": [ "koszul duality", "functors preserve semisimplicity", "common sheaf functors", "l-adic perverse sheaves", "beilinson-ginzburg-soergel states" ], "note": { "typesetting": "TeX", "pages": 76, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2011arXiv1102.2820A" } } }