University of Toronto's Symplectic Geometry Seminar

Abstract: I will report on joint work with A. Weinstein, M. Crainic and C. Zhu, and related ideas of P. Xu. I will show how the correspondence between Poisson manifolds and symplectic groupoids (analogous to the correspondence between Lie algebras and Lie groups) can be extended to the realm of (twisted) Dirac geometry. This generalization provides a natural framework for the "infinitesimal" description of quasi-hamiltonian actions and Lie-group valued moment maps of Alekseev, Malkin and Meinrenken.