On the existence of a Hofer type metric for Poisson manifolds

An analogue of the Hofer metric [Formula: see text] on the Hamiltonian group [Formula: see text] of a Poisson manifold [Formula: see text] can be defined, but there is the problem of its nondegeneracy. First, we observe that [Formula: see text] is a genuine metric on [Formula: see text], when the union of all proper leaves of the corresponding symplectic foliation is dense. Next, we deal with the important class of integrable Poisson manifolds. Recall that a Poisson manifold is called integrable, if it can be realized as the space of units of a symplectic groupoid. Our main result states that [Formula: see text] is a Hofer type metric for every Poisson manifold, which admits a Hausdorff integration.

Formal Lagrangian Operad

Given a symplectic manifoldM, we may define an operad structure on the the spacesOkof the Lagrangian submanifolds of(M¯)k×Mvia symplectic reduction. IfMis also a symplectic groupoid, then its multiplication space is an associative product in this operad. Following this idea, we provide a deformation theory for symplectic groupoids analog to the deformation theory of algebras. It turns out that the semiclassical part of Kontsevich's deformation ofC∞(ℝd) is a deformation of the trivial symplectic groupoid structure ofT∗ℝd.