Integrality Properties of Topological Fundamental Groups

Hélène Esnault

The talk is based on joint work with Michael Groechenig and Johan de Jong. We single out integrality properties of the topological fundamental group of smooth quasi-projective complex varieties which rely on the Langlands program (both arithmetic and geometric) and yield an obstruction for a finitely presented group to be the fundamental group of a smooth quasiprojective variety.

https://www.ias.edu/video/integrality-properties-topological-fundamental-groups