Lorentz gauge and Gribov ambiguity in the compact lattice U(1) theory
The Gribov ambiguity problem is studied for compact U(1) lattice theory within the Lorentz gauge. In the Coulomb phase, it is shown that apart from double Dirac sheets all gauge (i.e. Gribov) copies originate mainly from the zero-momentum modes of the gauge fields. The removal of the zero–momentum modes turns out to be necessary for reaching the absolute maximum of the gauge functional F(θ) . A new gauge fixing procedure – zero-momentum Lorentz gauge – is proposed.
Gauge fixing ambiguity and photon propagators in compact U(1) lattice gauge theory
Abstract We present the first numerical evidence of Gribov copies on a lattice. Photon propagators are numerically studied under the non-linear gauge condition ∂ μ sin θ μ = 0, where θ μ ' s are gauge potentials defined on a lattice. It is shown that this standard lattice Landau gauge condition is not unique. In the Coulomb phase a correct free propagator is obtained only after removing this ambiguity.
Zero-momentum contribution to wilson loops in periodic boxes
Abstract We compute the zero-momentum finite-size effects in non-abelian gauge theories. In some cases, these effects are to lowest-order identical for lattice and continuum theories and are of the order of a few percent for an SU(3) gauge theory in four dimensions.