Séance du 12 septembre 2014

Lieu : Jussieu, Salle 15-25-502  (ATTENTION: Lieu inhabituel!)

11:00  Joanna Nelson (Columbia)
    Cylindrical contact homology in dimension 3 via intersection theory and more.

Abstract: After reviewing the difficulties in proving d²=0 for dynamically convex contact manifolds, we explain how intersection theory and automatic transversality come to the rescue, as implemented by Hutchings-Nelson.  So that these methods do not remain shrouded in mystery, we provide an overview of the relevant ideas from intersection theory for pseudoholomorphic in 4-dimensional symplectizations a la Siefring and Hutchings.  Time permitting we end with a brief sketch of how to obtain invariance of cylindrical contact homology over Q via nonequivariant formulations, obstruction bundle gluing, domain dependent almost complex structures, and S¹-equivariant constructions.  The discussion of invariance is based on work in progress by Hutchings-Nelson..

14:00  Denis Auroux (Berkeley)

   Tores lagrangiens monotones et géométrie tropicale.

NB: Séance conjointe avec le séminaire "Géométrie et topologie" organisée par G Mikhalkin et Ilia Itenberg (Page du séminaire)

16:00  Penka Georgieva (IMJ-PRG)

    Orientability in real Gromov-Witten theory.

Résumé: The orientability problem in real Gromov-Witten theory is
one of the fundamental hurdles to enumerating real curves. In this
talk I will describe topological conditions on the target manifold
which ensure that the uncompactified moduli spaces of real maps are
orientable for all genera of and for all types of involutions on the
domain. In the case of a fixed-point free involution on the target the
result yields real Gromov-Witten invariants of arbitrary genus. This
is a joint work with A. Zinger..

Prochaines séances: 7/11 (A. Wand, R.C.A.M. van der Vorst, ?) - 5/12 (N. Vichery, M. Mazzuchelli, J. Kang) - 9/01 (J. Fine, ?, ?). Attention: pas de séance le 3/10.