Symplectix 26 juin 2020

 Séance en visioconférence ( lien sur demande à symplectix@gmail.com ) à 13h45

Lien: http://bigbluebutton3.imj-prg.fr/b/cla-jeh-jn7

Gleb Smirnov (ETHZ)

Title: Flops and non-Hamiltonian loops of diffeomorphisms

Abstract: In this talk, we will look at the topological structure of the identity component of the diffeomorphism group of algebraic surfaces. The main statement is simple: a simply-connected algebraic surface admits a loop of diffeomorphisms that is not homotopic to any loop of Hamiltonian diffeomorphisms. We will prove this statement under the mild assumption that our surface is a smoothing of a surface with a single double point singularity.

A noter, le vendredi à 15h15 heure de Paris : Symplectic Zoominar (CRM-Montreal, Princeton/IAS, Tel Aviv, and Paris):   https://dms.umontreal.ca/~cornea/Seminar.html

Symplectix 12 juin 2020

Séance en visioconférence ( lien sur demande à symplectix@gmail.com ) à 13h45

lien: http://bigbluebutton3.imj-prg.fr/b/cla-jeh-jn7

Vukašin Stojisavljević (Tel Aviv)

Title: Symplectic Banach-Mazur distance and persistence modules

Abstract: Denote by C_M the space of fiberwise star-shaped domains in the cotangent bundle of a closed manifold M. C_M can be equipped with a distance called symplectic Banach-Mazur distance and denoted by d_SBM. This distance is a non-linear version of the classical Banach-Mazur distance and is constructed using symplectic embeddings. Our main goal will be to study the large-scale geometry of the space (C_M,d_SBM). The main technical ingredient we use is stability of barcodes coming from filtered symplectic homology, viewed as a persistence module, with respect to d_SBM. If time permits, I will also discuss applications of similar methods to stability of closed geodesics with respect to perturbations of Riemannian metrics. The talk is based on a joint work with Jun Zhang.

A noter, le vendredi à 15h15 heure de Paris : Symplectic Zoominar (CRM-Montreal, Princeton/IAS, Tel Aviv, and Paris):   https://dms.umontreal.ca/~cornea/Seminar.html