4:00 pm Monday, November 15, 2010
Topology Seminar: Mapping class groups at different levels
by
Richard Kent [mail] (University of Wisconsin, Madison) in HB 427
It is a theorem of Bass, Lazard, and Serre, and, independently, Mennicke, that the special linear group SL(n,Z) enjoys the congruence subgroup property when n is at least 3. This property is most quickly described by saying that the profinite completion of the special linear group injects into the special linear group of the profinite completion of Z. There is a natural analog of this property for mapping class groups of surfaces. Namely, one may ask if the profinite completion of the mapping class group embeds in the outer automorphism group of the profinite completion of the surface group. M. Boggi has a program to establish this property for mapping class groups. I'll discuss some partial results, and what remains to be done. Host Department: Rice University-Mathematics
Submitted by andyp@rice.edu |
