Contact structures as Dirac structures and their associated Poisson algebras

Abstract

We give a description of contact structures on smoothmanifolds as Dirac structures, and we compute their associated Poisson algebras of admissible functions. We also revisit the notion of moment map associated to smooth actions on Lie groups on contact manifolds, we show that a contact moment map induces a moment map in the Dirac sense as defined in [3], and this map induces a natural morphism of Lie algebras of vector fields, admissible functions and infinitesimal symmetries.