Stratified Obstruction Systems for Equivariant Moduli Problems and   Invariant Euler cycles
  The purpose of this paper is to study finite dimensional equivariant moduli problems from the viewpoint of stratification theory. We show that there exists a stratified obstruction system for a finite dimensional equivariant moduli problem. In addition, we define a coindex for a G-vector bundle which is determined by the G-action on the vector bundle and prove that if the coindex of an oriented equivariant moduli problem is bigger than 1, then we obtain an invariant Euler cycle via equivariant perturbation. In particular, we get a localization formula for the stratified transversal intersection of S1-moduli problems. 
Xiangdong Yang
math.GT