GAUGE GROUP TQFT AND IMPROVED PERTURBATIVE YANG-MILLS THEORY

We reinterpret the Faddeev-Popov gauge-fixing procedure of Yang-Mills theories as the definition of a topological quantum field theory for g auge group elements depending on a background connection. This has the advantage of relating topological gauge-fixing ambiguities to the glo bal breaking of a supersymmetry. The global zero modes of the Faddeev- Popov ghosts are handled in the context of an equivariant cohomology w ithout breaking translational invariance. The gauge-fixing involves co nstant fields which play the role of moduli and modify the behavior of Green functions at subasymptotic scales. At the one loop level physic al implications from these power corrections are gauge invariant.