Speaker:  Margaret Readdy

Title:   Combinatorial identities related to the calculation of the cohomology of Siegel modular varieties

Abstract:

In the computation of the intersection cohomology of Shimura varieties, or of the L² cohomology of equal rank locally symmetric spaces, combinatorial identities involving averaged discrete series characters of real reductive groups play a large technical role. These identities can become very complicated and are not always well-understood. We propose a geometric approach to these identities in the case of Siegel modular varieties using the combinatorial properties of the Coxeter complex of the symmetric group

Joint work with Richard Ehrenborg and Sophie Morel.