Title: The stable cohomology of congruence subgroups
Speaker: Frank Calegari
Speaker Info: Northwestern
Brief Description:
Special Note:
Abstract:
In a fixed degee d, the integral homology groups H_d(SL_N(Z),Z) are independent of N for large N, and are intimately related to the algebraic K-theory of Z. On the other hand, if Gamma_N(P) is the congruence subgroup of Gamma_N, then H_d(Gamma_N(Z),Z) will *not* be stable, even for d = 1. We show how one can repair this (at least conjecturally), and why these groups ultimately are connected to p-adic zeta functions.Date: Monday, February 4, 2013