most recent 30 from http://mathoverflow.net 2013-05-22T15:58:39Z http://mathoverflow.net/feeds/question/94425 http://www.creativecommons.org/licenses/by-nc/2.5/rdf http://mathoverflow.net/questions/94425/finite-index-subgroups-of-the-mapping-class-group-with-geometric-meaning berl13 2012-04-18T16:32:50Z 2012-04-18T21:10:51Z

<p>I have got a question that is perhaps not precise in a mathematical sense. Is there a classification of all coverings of the moduli space of Riemann surfaces which are moduli spaces themselves, that is, they parametrize some geometric structure on a surface.</p>

http://mathoverflow.net/questions/94425/finite-index-subgroups-of-the-mapping-class-group-with-geometric-meaning/94461#94461 Lee Mosher 2012-04-18T21:01:14Z 2012-04-18T21:10:51Z

<p>I doubt there is a "classification", but there are some interesting examples. Two which come to mind: Harer's description of the moduli space of a Riemann surface with spin structure; and Torelli space. </p> <p>EDIT: Oops, I forgot to read your title, I just read the text. Torelli space is an infinite rank covering of moduli space.</p>