Invariants of real symplectic four-manifolds out of reducible and cuspidal curves
We construct invariants under deformation of real symplectic four-manifolds. These invariants are obtained by counting three different kinds of real rational -holomorphic curves which realize a given homology class and pass through a given real configuration of (the appropriate number of) points. These curves are cuspidal curves, reducible curves and curves with a prescribed tangent line at some real point of the configuration. They are counted with respect to some sign defined by the parity of...