arXiv:1007.3015 Chiral equivariant cohomology of a point: a first look from arXiv Front: math.AT by Andrew R. Linshaw The chiral equivariant cohomology contains and generalizes the classical equivariant cohomology of a manifold M with an action of a compact Lie group G. For any simple G, there exist compact manifolds with the same classical equivariant cohomology, which can be distinguished by this invariant. When M is a point, this cohomology is an interesting conformal vertex algebra whose structure is still mysterious. In this paper, we scratch the surface of this object in the case G=SU(2).
nLab page on Chiral equivariant cohomology