{ "id": "1405.0318", "version": "v2", "published": "2014-05-01T22:31:32.000Z", "updated": "2014-05-07T19:47:02.000Z", "title": "Generic representation theory of finite fields in nondescribing characteristic", "authors": [ "Nicholas J. Kuhn" ], "comment": "11 pages revised version: reference to Helmstutler's work is updated", "categories": [ "math.RT" ], "abstract": "Let Rep(F;K) denote the category of functors from finite dimensional F-vector spaces to K-modules, where F is a field and K is a commutative ring. We prove that, if F is a finite field, and Char F is invertible in K, then the K-linear abelian category Rep(F;K) is equivalent to the product, over all k=0,1,2, ..., of the categories of K[GL(k,F)]-modules. As a consequence, if K is also a field, then small projectives are also injective in Rep(F;K), and will have finite length. Even more is true if Char K = 0: the category Rep(F;K) will be semisimple. In a last section, we briefly discuss \"q=1\" analogues and consider representations of various categories of finite sets. The main result follows from a 1992 result by L.G.Kovacs about the semigroup ring K[M_n(\\F)].", "revisions": [ { "version": "v2", "updated": "2014-05-07T19:47:02.000Z" } ], "analyses": { "subjects": [ "18A25", "20G05", "20M25", "16D90" ], "keywords": [ "generic representation theory", "finite field", "nondescribing characteristic", "finite dimensional f-vector spaces", "k-linear abelian category rep" ], "note": { "typesetting": "TeX", "pages": 11, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1405.0318K" } } }