{ "id": "0712.2614", "version": "v4", "published": "2007-12-17T01:53:21.000Z", "updated": "2010-11-23T15:24:59.000Z", "title": "Characters of unipotent groups over finite fields", "authors": [ "Mitya Boyarchenko" ], "comment": "Version 4, 81 pages, LaTeX. Main change compared to the previous version: the term \"$L$-packet\" has been replaced with \"$\\mathbb{L}$-packet\", which is short for \"Lusztig packet\" (to distinguish it from Langlands' notion of an $L$-packet)", "journal": "Selecta Mathematica, Vol. 16 (2010), No. 4, pp. 857--933", "categories": [ "math.RT" ], "abstract": "Let G be a connected unipotent group over a finite field F_q with q elements. In this article we propose a definition of L-packets of complex irreducible representations of the finite group G(F_q) and give an explicit description of L-packets in terms of the so-called \"admissible pairs\" for G. We then apply our results to show that if the centralizer of every geometric point of G is connected, then the dimension of every complex irreducible representation of G(F_q) is a power of q, confirming a conjecture of V. Drinfeld. This paper is the first in a series of three papers exploring the relationship between representations of a group of the form G(F_q) (where G is a unipotent algebraic group over F_q), the geometry of G, and the theory of character sheaves.", "revisions": [ { "version": "v4", "updated": "2010-11-23T15:24:59.000Z" } ], "analyses": { "keywords": [ "finite field", "complex irreducible representation", "unipotent algebraic group", "connected unipotent group", "geometric point" ], "tags": [ "journal article" ], "note": { "typesetting": "LaTeX", "pages": 81, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2007arXiv0712.2614B" } } }