Almost Complex Structures on Symplectic Manifolds
Almost Complex Structure
An almost complex structure on a smooth manifold
is a smooth bundle map such that . The pair is called an almost complex manifold.
Compatible Almost Complex Structures
Let
be a symplectic manifold. An almost complex structure on is said to be compatible (with , or -compatible) if and for all non-zero . That is admits a Riemannian metric on .