Equivariant gauge fixing of SU(2) lattice gauge theory - art. no. 014508.

I construct a lattice gauge theory (LGT) with a discrete Z(2) structure gro up and an equivariant BRST symmetry that is physically equivalent to the st andard SU(2) LGT. The measure of this Z(2) LGT is invariant under nll the d iscrete symmetries of the lattice and its partition function does not vanis h. The topological lattice theories (TLT) that localize on the moduli space s are explicitly constructed and their BRST symmetry is exhibited. The ghos ts of the Z(2)-invariant local LGT are integrated in favor of a nonlocal bo sonic measure. In addition to the SU(2) link variables and the coupling g(2 ), this effective bosonic measure also depends on an auxiliary gauge invari ant site variable of canonical dimension two and on a gauge parameter alpha . The relation between the expectation value of the auxiliary field, the ga uge parameter cu and the lattice spacing a is obtained to lowest order in t he loop expansion. In four dimensions and the critical limit this expectati on value is a physical scale proportional to Lambda(L) in the gauge alpha = g(2)(11 - n(f))/24 + O(g(4)). Implications for the loop expansion of obser vables in such a critical gauge are discussed. [S0556-2821(99)00401-4].