Séminaires : Séminaire d'Algèbres d'Opérateurs

Equipe(s) : ao,
Responsables :Pierre Fima, François Le Maître, Romain Tessera
Email des responsables :
Salle : 1013
Adresse :Sophie Germain

Orateur(s) Lachlan MacDonald - University of Wollongong,
Titre The Godbillon-Vey invariant in equivariant KK-theory
Horaire14:30 à 15:30
RésumeThe Godbillon-Vey invariant is a de Rham cohomology class associated to any transversely orientable foliated manifold, which can be explicitly constructed at the level of differential forms. Using Hopf cyclic theory, Connes and Moscovici have given in codimension 1 an explicit formula for the Godbillon-Vey invariant as a cyclic cocycle on a convolution algebra associated to the foliation. In this talk I will realise the Connes-Moscovici cocycle as the Chern character of a semifinite spectral triple built using groupoid equivariant KK-theory, and show how the construction generalises to foliations of arbitrary codimension.
AdresseSophie Germain