Multi-instanton calculus and equivariant cohomology

Abstract

We present a systematic derivation of multi-instanton amplitudes in terms of ADHM equivariant cohomology. The results rely on a supersymmetric formulation of the localization formula for equivariant forms. We examine the cases of N = 4 and N = 2 gauge theories with adjoint and fundamental matter. © SISSA/ISAS 2003.