# Séminaire de géométrie analytique

le jeudi de 16h15 à 17h15 en salle 016

Archives du séminaire

Responsable : Bert WIEST

### Mai 2017

4 mai Journée de présentation des candidats pour le poste de géométrie

11 mai James Farre, Utah
3rd bounded cohomology of Kleinian groups

We explore the bounded cohomology of Kleinian groups. More concretely we discuss how certain hyperbolic structures on 3-manifolds give rise to different bounded classes in degree 3.

18 mai

25 mai Vacances (Ascension)

### Juin 2017

1 juin

8 juin Simon Brandhorst, Hannover
Minimal Salem numbers on supersingular K3 surfaces

The entropy of a surface automorphism is either zero or the logarithm of a Salem number, that is an algebraic integer $\lambda>1$ which is conjugate to $1/\lambda$ and all whose other conjugates lie on the unit circle.

In the case of a complex K3 surface McMullen gave a strategy to decide whether a given Salem number arises in this way. To do this he combined methods from linear programming, number fields, lattice theory and the Torelli theorems. In this talk we extend these methods to automorphisms of supersingular K3 surfaces using the crystalline Torelli theorems and apply them in the case of characteristic $5$.

This is joint work with Víctor González-Alonso.

15 juin

22 juin

29 juin

6 juilliet