GKM spaces and graphs

A projective variety with a complex torus acting on it is a GKM space if there are only a finite number of fixed points and a finite number of one dimensional orbits. (For instance flag varieties and toric varieties are such spaces.) Computing the equivariant cohomology rings of these spaces is equivalent to to a problem in graph theory the solution to which involves some interesting "topological" invariants of graphs.

No previous knowledge of equivariant cohomology is required. This talk will be accessible to general audience.