{ "id": "math/0010310", "version": "v3", "published": "2000-10-31T01:42:16.000Z", "updated": "2001-11-23T20:01:16.000Z", "title": "The mapping class group of a genus two surface is linear", "authors": [ "Stephen J. Bigelow", "Ryan D. Budney" ], "comment": "Published by Algebraic and Geometric Topology at http://www.maths.warwick.ac.uk/agt/AGTVol1/agt-1-34.abs.html", "journal": "Algebr. Geom. Topol. 1 (2001) 699-708", "categories": [ "math.GT", "math.AT", "math.GR" ], "abstract": "In this paper we construct a faithful representation of the mapping class group of the genus two surface into a group of matrices over the complex numbers. Our starting point is the Lawrence-Krammer representation of the braid group B_n, which was shown to be faithful by Bigelow and Krammer. We obtain a faithful representation of the mapping class group of the n-punctured sphere by using the close relationship between this group and B_{n-1}. We then extend this to a faithful representation of the mapping class group of the genus two surface, using Birman and Hilden's result that this group is a Z_2 central extension of the mapping class group of the 6-punctured sphere. The resulting representation has dimension sixty-four and will be described explicitly. In closing we will remark on subgroups of mapping class groups which can be shown to be linear using similar techniques.", "revisions": [ { "version": "v3", "updated": "2001-11-23T20:01:16.000Z" } ], "analyses": { "subjects": [ "20F36", "57M07", "20C15" ], "keywords": [ "mapping class group", "faithful representation", "similar techniques", "lawrence-krammer representation", "braid group" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }