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 ˇSevera class—and for Dirac structures.

We construct a Legendrian 2-torus in the 1-jet space of $S^1 x $\Bbb R$ (or of $\Bbb R^2$) from a loop of Legendrian knots in the 1-jet space of $\Bbb R$. The differential graded algebra (DGA) for the Legendrian contact homology of the torus is explicitly computed in terms of the DGA of the knot and the monodromy operator of the loop. The contact homology of the torus is shown to depend only on the chain homotopy type of the monodromy operator. The construction leads to many new examples of Legendrian knotted tori. In particular, it allows us to construct a Legendrian torus with DGA which does not admit any augmentation (linearization) but which still has non-trivial homology, as well as two Legendrian tori with isomorphic linearized contact homologies but with distinct contact homologies.

We use the recently defined knot Floer homology invariant for transverse knots to show that certain pairs of transverse knots with the same self-linking number are not transversely isotopic. We also show that some of the algebraic refinements of knot Floer homology lead to refined versions of these invariants, distinguishing additional transversely non-isotopic knots with the same self-linking number.