Yukinobu Toda

Title: Curve counting theories via stable objects in the derived  
category

Abstract:  The generating series of Donaldson-Thomas invariants is  
expected to have several properties, e.g. rationality, DT-PT  
correspondence, DT-NCDT correspondence and flop invariance. In this  
talk, I show that another generating series without virtual  
fundamental cycle has all these properties. I use generalized  
Bridgeland stability conditions on derived categories, and the wall- 
crossing formula.