Séminaire de Géométrie Arithmétique Paris-Pékin-Tokyo

On the vanishing of cohomology for certain Shimura varieties

by Prof. A. Caraiani (Imperial College)

mercredi 17 janvier 2018 de au (Europe/Paris)
at IHES ( Centre de conférences Marilyn et James Simons )
Le Bois Marie 35, route de Chartres 91440 Bures-sur-Yvette
Description

I will prove that the compactly supported cohomology of certain unitary or symplectic Shimura varieties at level Gamma_1(p^\infty) vanishes above the middle degree. The key ingredients come from p-adic Hodge theory and studying the Bruhat decomposition on the Hodge-Tate flag variety. I will describe the steps in the proof using modular curves as a toy model. I will also mention an application to Galois representations for torsion classes in the cohomology of locally symmetric spaces for GL_n. This talk is based on joint work in preparation with D. Gulotta, C.Y. Hsu, C. Johansson, L. Mocz, E. Reineke, and S.C. Shih.

Organisé par Ahmed Abbes
Contact Email: cecile@ihes.fr