Equivariant intersection cohomology of the circle actions

Abstract : In this paper, we prove that the orbit space $B$ and the Euler class of the action $\Phi \colon \sbat \times X \to X$ determine both the equivariant intersection cohomology of the pseudomanifold $X$ and its localization. We also construct a spectral sequence converging to the equivariant intersection cohomology of $X$ whose third term is described in terms of the intersection cohomology of $B$.