{ "id": "math/0210408", "version": "v4", "published": "2002-10-26T16:42:13.000Z", "updated": "2004-04-18T15:24:11.000Z", "title": "Representations of finite groups on Riemann-Roch spaces", "authors": [ "David Joyner", "Will Traves" ], "comment": "24 pages, significant revision", "categories": [ "math.AG", "cs.IT", "math.GR", "math.IT" ], "abstract": "We study the action of a finite group on the Riemann-Roch space of certain divisors on a curve. If $G$ is a finite subgroup of the automorphism group of a projective curve $X$ over an algebraically closed field and $D$ is a divisor on $X$ left stable by $G$ then we show the irreducible constituents of the natural representation of $G$ on the Riemann-Roch space $L(D)=L_X(D)$ are of dimension $\\leq d$, where $d$ is the size of the smallest $G$-orbit acting on $X$. We give an example to show that this is, in general, sharp (i.e., that dimension $d$ irreducible constituents can occur). Connections with coding theory, in particular to permutation decoding of AG codes, are discussed in the last section. Many examples are included.", "revisions": [ { "version": "v4", "updated": "2004-04-18T15:24:11.000Z" } ], "analyses": { "subjects": [ "14H37", "20C20", "94B27", "11T71", "05E20" ], "keywords": [ "riemann-roch space", "finite group", "irreducible constituents", "automorphism group", "natural representation" ], "note": { "typesetting": "TeX", "pages": 24, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2002math.....10408J" } } }