RéGA

Emiliano Ambrosi "Specialization of representations of the étale fundamental group and applications" 16h-17h

Europe/Paris
Salle 314 (IHP)

Salle 314

IHP

Description

Emiliano Ambrosi (Ecole Polytechnique)

Specialization of representations of the étale fundamental group and applications. 

Let X → S be a family of smooth projective varieties over a finitely generated field k.

For every closed point s of S we have an l-adic representation of the absolute Galois group of k on the l-adic étale cohomology of the fiber of the morphism in s. We will discuss how the image of these representations vary when s is varying in S(k). Finally we will show how these results can be used to study the specialization of Néron severi group.