Is there any reference for equivariant Riemann-Roch formula: book, paper, notes or something? I want to compute the weight of the action of C^* on the top wedge of cohomology group.
You also have some lecture notes on the web page of Michel Brion here.
This paper of N. Berline and M. Vergne is well written (but is more "Lie Group theoretic" than the previous references and it is written in french...).
You could try one or all of these (same authors):
Dan Edidin and William Graham:
Algebraic cycles and completions of equivariant K-theory here
Riemann-Roch for equivariant Chow groups here
Equivariant intersection theory here