Séminaire à 10h45 puis à 13h45 en ligne via BBB : http://bigbluebutton3.imj-prg.fr/b/cla-jeh-jn7
10h45 : Johan Asplund (Uppsala)
Title : Chekanov-Eliashberg dg-algebras for singular Legendrians
Abstract : The Chekanov-Eliashberg dg-algebra is a holomorphic
curve
invariant associated to a Legendrian submanifold of a contact
manifold.
In this talk we explain how to extend the definition to singular
Legendrian submanifolds admitting a Weinstein neighborhood. Via
the
Bourgeois-Ekholm-Eliashberg surgery formula, the new definition
gives
direct geometric proof of the pushout diagrams and stop removal
formulas
in partially wrapped Floer cohomology of Ganatra-Pardon-Shende. It
furthermore leads to a proof of the conjectured surgery formula
relating
partially wrapped Floer cohomology to Chekanov--Eliashberg
dg-algebras
with coefficients in chains on the based loop space. This talk is
based
on joint work with Tobias Ekholm.
13h45 : Jonathan Zung (Princeton).
Title : Reeb flows transverse to foliations
Abstract : Eliashberg and Thurston showed that, roughly speaking, C^2 taut foliations on 3-manifolds can be approximated by tight contact structures. I will explain a new approach to this theorem which allows one to control the resulting Reeb flow and hence produce many hypertight contact structures. Along the way, I will explain how harmonic transverse measures may be used to understand the holonomy of foliations.
