{ "id": "0809.4477", "version": "v3", "published": "2008-09-25T19:30:45.000Z", "updated": "2011-10-28T03:31:47.000Z", "title": "The second rational homology group of the moduli space of curves with level structures", "authors": [ "Andrew Putman" ], "comment": "27 pages, 4 figures, mild revision. To appear in Adv. Math", "journal": "Adv. Math. 229 (2012), 1205-1234", "categories": [ "math.GT", "math.AG", "math.AT" ], "abstract": "Let $\\Gamma$ be a finite-index subgroup of the mapping class group of a closed genus $g$ surface that contains the Torelli group. For instance, $\\Gamma$ can be the level $L$ subgroup or the spin mapping class group. We show that $H_2(\\Gamma;\\Q) \\cong \\Q$ for $g \\geq 5$. A corollary of this is that the rational Picard groups of the associated finite covers of the moduli space of curves are equal to $\\Q$. We also prove analogous results for surface with punctures and boundary components.", "revisions": [ { "version": "v3", "updated": "2011-10-28T03:31:47.000Z" } ], "analyses": { "keywords": [ "second rational homology group", "moduli space", "level structures", "spin mapping class group", "rational picard groups" ], "tags": [ "journal article" ], "publication": { "publisher": "Elsevier", "journal": "Adv. Math." }, "note": { "typesetting": "TeX", "pages": 27, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2008arXiv0809.4477P" } } }