Registration link:https://www.wjx.top/vm/hIyYeIS.aspx# SpeakerGerard van der Geer is professor emeritus at the University of Amsterdam He works in algebraic geometry and arithmetic geometry with emphasis on moduli spaces and modular forms. He worked on Hilbert modular surfaces,curves over finite fields, cycle classes on moduli of abelian varieties and on modular forms. He got a honorary doctora...
Abstract:Some Shimura varieties can be interpreted as moduli spaces of curves. In such cases this can be used to get information about modular forms. We discuss a ball quotient related to moduli of curves of genus three. We study cohomology of local systems and calculate the traces of Hecke operators by counting points on curves over finite fields. We also construct all vector-valued Picard mo...