Title: On the cohomology of some non-compact Shimura varieties
Speaker: Professor Sophie Morel
Speaker Info: IAS
Brief Description:
Special Note:
Abstract:
In this talk, I will explain how the method originally developed by Ihara, Langlands and Kottwitz to compute the cohomology of a Shimura variety (use the Grothendieck-Lefschetz fixed point formula in positive characteristic to calculate the trace on the cohomology of a power of Frobenius at a good place times a Hecke operator trivial at that place, and then compare the result with Arthur's trace formula) applies to intersection cohomology of the Satake-Baily-Borel compactification of the Shimura varieties of unitary groups over Q and of the Siegel moduli varieties. I will also present applications to the calculation of the L-function of the intersection complex (for unitary groups and small-dimensional symplectic groups) and some applications involving base change from quasi-split unitary groups to general linear groups.Date: Tuesday, November 11, 2008