Séance du 3 mars 2017

Lieu: IHP, salle 201



11:00  Luis Hernandez Corbato (Madrid)
The conjugation method in symplectic dynamics.
Abstract: The conjugation method (also known as Anosov-Katok method) allows to produce diffeomorphisms with prescribed properties on the asymptotical distribution of their orbits. In the talk we discuss how to adapt this method from arguments of Fathi and Herman to the symplectic setting. We obtain minimal symplectomorphisms and strictly ergodic contactomorphisms on manifolds which admit a locally free S¹-action by symplectomorphisms and contactomorphisms. This is joint work with Francisco Presas.

14:15 Baptiste Chantraine (Nantes)  
Isotopies legendriennes positives et homologie de Floer.
Abstract: Dans une variété de contact coorientée, une isotopie legendrienne est dite positive si elle évolue dans la direction positive transverse à la structure de contact. Les comportements globaux des isotopies positives diffèrent de ceux des isotopies legendriennes. Dans cet exposé j'expliquerai comment extraire de l'information dans le complexe de Floer associé à une paire de cobordismes lagrangiens (récemment défini en collaboration avec G. Dimitroglou Rizell, P. Ghiggini et R. Golovko) pour donner des obstructions à l'existence de certaines isotopies positives. Cette méthode permet de retrouver toutes les obstructions connues à ce jour et donne de nouveaux exemples. Collaboration avec V. Colin et G. Dimitroglou Rizell.


16:00  Jian Wang (Bonn)  
Some results on Hamiltonian homeomorphisms on aspherical closed surfaces.

Abstract: On closed symplectically aspherical manifolds, Schwarz proved a classical result that the action function of a nontrivial Hamiltonian diffeomorphism is not constant by using Floer homology. In this talk, we will show how to generalize Schwarz's theorem to the C^0-case on closed aspherical surfaces. As application, we prove that the contractible fixed points set (and consequently the fixed points set) of a non-trivial Hamiltonian homeomorphism is not connected.



Prochaines séances: 31 mars (I. Itenberg, ?, ?), 5 mai (P. Ghiggini,?,?), 2 juin (H. Gao, ?, ?)


Autre activité symplectique à Paris:
- Séminaire Nantes-Orsay,

Séance du 6 janvier 2017

Lieu: IHP, salle 201
Attention, pas d'exposé le matin.

RDV à 12:15 à l'IHP pour aller déjeuner, pour celles et ceux qui le souhaitent !

14:15 Luís Diogo (Columbia)  
Monotone Lagrangians in cotangent bundles of spheres.
Abstract: We show that there is a 1-parameter family of monotone Lagrangians in cotangent bundles of spheres with the following property: every (orientable spin) closed monotone Lagrangian with non-trivial Floer cohomology is not Hamiltonian-displaceable from either the zero-section or one of the Lagrangians in the family. The proof involves studying a version of the wrapped Fukaya category that includes monotone Lagrangians. This is joint work with Mohammed Abouzaid.


16:00  Maÿlis Limouzineau (Jussieu) 
Constructions of Legendrian knots and cobordisms together with generating functions .

Abstract: Among all Legendrian knots in the space J^1(R,R) = R x T*R, some can be obtained from graphs of functions by a classic and natural operation~: by taking the contour of generating functions. We focus on this very restrictive class of Legendrians, and offer constructions to help studying them. In this talk, we will discuss in particular the related notion of cobordism~: that is Legendrian surfaces between Legendrian knots which are also contour of generating functions.



Prochaines séances: 3 mars (B. Chantraine, L. Hernandez Corbato, J. Wang), 31 mars (I. Itenberg, ?, ?)


Autre activité symplectique à Paris:
- Séminaire Nantes-Orsay,