{ "id": "1311.2434", "version": "v4", "published": "2013-11-11T13:14:17.000Z", "updated": "2014-02-24T13:01:30.000Z", "title": "Basic functions and unramified local L-factors for split groups", "authors": [ "Wen-Wei Li" ], "comment": "42 pages, largely revised", "categories": [ "math.RT", "math.NT" ], "abstract": "According to a program of Braverman, Kazhdan and Ng\\^o Bao Ch\\^au, for a large class of split unramified reductive groups $G$ and representations $\\rho$ of the dual group $\\hat{G}$, the unramified local $L$-factor $L(s,\\pi,\\rho)$ can be expressed as the trace of $\\pi(f_{\\rho,s})$ for a suitable function $f_{\\rho,s}$ with non-compact support whenever $\\mathrm{Re}(s) \\gg 0$. Such functions can be plugged into the trace formula to study certain sums of automorphic $L$-functions. It also fits into the conjectural framework of Schwartz spaces for reductive monoids due to Sakellaridis, who coined the term basic functions; this is supposed to lead to a generalized Tamagawa-Godement-Jacquet theory for $(G,\\rho)$. In this article, we derive some basic properties for the basic functions $f_{\\rho,s}$ and interpret them via invariant theory. In particular, their coefficients are interpreted as certain generalized Kostka-Foulkes polynomials defined by Panyushev. These coefficients can be encoded into a rational generating function.", "revisions": [ { "version": "v4", "updated": "2014-02-24T13:01:30.000Z" } ], "analyses": { "subjects": [ "22E50", "11F70" ], "keywords": [ "unramified local l-factors", "split groups", "term basic functions", "large class", "non-compact support" ], "note": { "typesetting": "TeX", "pages": 42, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1311.2434L" } } }