Observables in Topological Yang-Mills Theories With Extended Shift   Supersymmetry
  We present a complete classification, at the classical level, of the observables of topological Yang-Mills theories with an extended shift supersymmetry of N generators, in any space-time dimension. The observables are defined as the Yang-Mills BRST cohomology classes of shift supersymmetry invariants. These cohomology classes turn out to be solutions of an N-extension of Witten's equivariant cohomology. This work generalizes results known in the case of shift supersymmetry with a single generator. 
Clisthenis P. Constantinidis, Olivier Piguet and Wesley Spalenza