Graded geometry and generalized reduction

Abstract

We present general reduction procedures for Courant, Dirac and generalized complex structures, in particular when a group of symmetries is acting. We do so by taking the graded symplectic viewpoint on Courant algebroids and carrying out graded symplectic reduction, both in the coisotropic and hamiltonian settings. Specializing the latter to the exact case, we recover in a systematic way the reduction schemes of Bursztyn-Cavalcanti-Gualtieri.

85 pages. v3: Sections 2.2 , 2.4.2, 2.4.4. and 3.2 were largely rewritten. Example 2.9 was added. Version accepted for publication