Talk:SQ universal group

From Wikipedia, the free encyclopedia

[edit] Definition

The original definition of SQ-universality that appeared on this page was incorrect and was in fact the definion of SQ-universality for the class of finite groups. Bernard Hurley 00:05, 23 September 2006 (UTC)

[edit] Examples

I'd like to request some examples added to this article. For example, I beleive that SL(2,Z) is SQ-universal, since it has the the free group in two generators as a subgroup. Since its isomorphic to the braid group B_3, and all other higher braid groups B_n have B_3 as a subgroup, that implies all braid groups (except the trivial B_1 and the B_2=Z) are SQ universal. Right? Ditto for mapping class group.

Less clear to me is when a monodromy might be SQ-universal; but given the close relationship to braids and mapping classes, I'd think some general statements should be possible.. linas 22:53, 6 April 2007 (UTC)