Super-rigidity and bifurcations of embedded curves in Calabi-Yau 3-folds

I will describe my recent work, joint with Shaoyun Bai, which studies a class of bifurcations of moduli spaces of embedded pseudo-holomorphic curves in symplectic Calabi-Yau 3-folds and their associated obstruction bundles. As an application, we are able to give a direct definition of the Gopakumar-Vafa invariant in a special case.