{ "id": "math/0601750", "version": "v4", "published": "2006-01-31T04:55:15.000Z", "updated": "2008-09-04T19:01:35.000Z", "title": "Surfaces in a background space and the homology of mapping class groups", "authors": [ "Ralph L. Cohen", "Ib Madsen" ], "comment": "final version, to be published in the Proceedings of the Seattle Summer Institute in Algebraic Geometry, Proc. Symp. Pure Math., AMS", "categories": [ "math.GT", "math.AT" ], "abstract": "In this paper we study the topology of the space of Riemann surfaces in a simply connected space X, S_{g,n} (X, \\gamma). This is the space consisting of triples, (F_{g,n}, \\phi, f), where F_{g,n} is a Riemann surface of genus g and n-boundary components, \\phi is a parameterization of the boundary, and f : F_{g,n} \\to X is a continuous map that satisfies a boundary condition \\gamma. We prove three theorems about these spaces. Our main theorem is the identification of the stable homology type of the space S_{\\infty, n}(X; \\gamma), defined to be the limit as the genus g gets large, of the spaces S_{g,n} (X; \\gamma). Our result about this stable topology is a parameterized version of the theorem of Madsen and Weiss proving a generalization of the Mumford conjecture on the stable cohomology of mapping class groups. Our second result describes a stable range in which the homology of S_{g,n} (X; \\gamma) is isomorphic to the stable homology. Finally we prove a stability theorem about the homology of mapping class groups with certain families of twisted coefficients. The second and third theorems are generalizations of stability theorems of Harer and Ivanov.", "revisions": [ { "version": "v4", "updated": "2008-09-04T19:01:35.000Z" } ], "analyses": { "subjects": [ "57R50", "30F99", "57M07" ], "keywords": [ "mapping class groups", "background space", "stability theorem", "riemann surface", "stable homology type" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2006math......1750C" } } }