A note on submanifolds and mappings in generalized complex geometry by
Izu VaismanABSTRACT. In generalized complex geometry, we revisit linear subspaces and submanifolds that have an induced generalized complex structure. We give an expression of the induced structure that allows us to deduce a smoothness criterion, we dualize the results to submersions and we make a few comments on generalized complex mappings. Then, we discuss submanifolds of generalized Kähler manifolds that have an induced generalized Kähler structure. These turn out to be the common invariant submanifolds of the two classical complex structures of the generalized Kähler manifold.
IntroductionInduced generalized complex structures of submanifolds were introduced and studied in [3] and the study was continued in [2,6,12], etc. After a preliminary Section 2, where we recall known results, in Section 3, we give a general expression of the induced structure and derive a smoothness criterion. The results are dualized to submersions and a few remarks on more general mappings are made, including a proposed, new definition of generalized complex mappings. In Section 4, we consider the generalized Hermitian and generalized Kähler case, which is known to be given by a 1-1 correspondence with quadruples (γ, ψ, J ± ), where γ is a metric, ψ is a 2-form and J ± are classical γ-compatible complex structures. Then, we define the notion of induced structure in a way that is compatible with the generalized complex case and is such that existence of the induced structure is equivalent to J ± -invariance. We work in the C ∞ -category and use the classical notation of Differential Geometry [8].* 2000 Mathematics Subject Classification: 53C56 .