Séance du 4 octobre 2019

Lieu: IHP, salle 201.

11:00 Slava Pimenov (Jussieu)
Bornological Manifolds and bounded group cohomology.
Abstract: We are interested in properties of the comparison map between bounded continuous cohomology and (unbounded) continuous cohomology of a topological group G, in particular whether it is an isomorphism. While in discreet case the question has been mostly settled, even for semisimple Lie groups very little is known. The term bornology formalizes idea of boundedness, similar to how topology does it for continuity. It is used extensively in functional analysis to study bounded linear operators. We propose a notion of bornological manifolds that may provide a framework that allows us to put geometric group properties, topological dynamics and analytic properties of topological vector spaces together, and use sheaf-theoretic methods to address this question. This is a joint work with Kobi Kremnitzer..

14:15 Jean-Paul Mohsen (Marseille)
Construction de sous-variétés complexes à courbure négative.
Abstract: Le premier but des techniques asymptotiques de Donaldson-Auroux était de transposer dans le cadre général de la géométrie symplectique certains résultats classiques de géométrie projective. Néanmoins, Donaldson avait noté que ces techniques avaient aussi des applications dans le cadre projectif. On présentera de nouveaux exemples de telles applications.

16:00 Yusuke Kawamoto (ENS).
Titre: C0 continuity of the spectral norm on non-symplectically aspherical manifolds.
Abstract: I will discuss the C0 continuity of the spectral norm on the group of Hamiltonian diffeomorphisms for some non-symplectically aspherical manifolds. The method is based on a recent work of Buhovski-Humiliere-Seyfaddini where they prove the continuity in the case of symplectically aspherical manifolds. In this talk, I focus to explain how to push their method to the non-symplectically aspherical case.

Prochaines séances: 8 novembre (Rosen, Theillière, Galant), 13 décembre (Albers, Golovko, Salchow), 10 janvier

Autre activité symplectique à Paris:
Séminaire Nantes-Orsay