Reduction of branes in generalized complex geometry

We show that certain submanifolds of generalized complex manifolds ("weak branes") admit a natural quotient which inherits a generalized complex structure. This is analog to quotienting coisotropic submanifolds of symplectic manifolds. In particular Gualtieri's generalized complex submanifolds ("branes") quotient to space-filling branes. Along the way we perform reductions by foliations (i.e. no group action is involved) for exact Courant algebroids - interpreting the reduced \v{S}evera class - and for Dirac structures.Comment: Final version, to apper in Journal of Symplectic Geometry. Proofs in section 5 simplified. 19 page

Simultaneous deformations of algebras and morphisms via derived brackets

We present a method to construct explicitly L-infinity algebras governing simultaneous deformations of various kinds of algebraic structures and of their morphisms. It is an alternative to the heavy use of the operad machinery of the existing approaches. Our method relies on Voronov's derived bracket construction.Comment: 20 pages. Final version, accepted for publication, and significantly shorter than version v1. Our previous submission arXiv:1202.2896v1 has been divided into two parts. The present paper contains the algebraic applications of the theory, while the geometric applications are the subject of the paper arXiv:1202.2896v2 ("Simultaneous deformations and Poisson geometry"

Variations on Prequantization

We extend known prequantization procedures for Poisson and presymplectic manifolds by defining the prequantization of a Dirac manifold P as a principal U(1)-bundle Q with a compatible Dirac-Jacobi structure. We study the action of Poisson algebras of admissible functions on P on various spaces of locally (with respect to P) defined functions on Q, via hamiltonian vector fields. Finally, guided by examples arising in complex analysis and contact geometry, we propose an extension of the notion of prequantization in which the action of U(1) on Q is permitted to have some fixed points.Comment: 33 pages; contribution to the proceedings of the conference Poisson 200