相关论文: Gribov horizon in Noncommutative QED
The quantization of non-Abelian gauge theories is known to be plagued by Gribov copies. Typical examples are the copies related to zero modes of the Faddeev-Popov operator, which give rise to singularities in the ghost propagator. In this…
We show that a necessary condition to have a positive Landau-gauge ghost propagator in d=2 Yang-Mills theories is a vanishing zero-momentum gluon propagator. Our proof is based on a careful scrutinizing of the ghost Dyson-Schwinger…
We discuss Faddeev-Popov quantization at the non-perturbative level and show that Gribov's prescription of cutting off the functional integral at the Gribov horizon does not change the Schwinger-Dyson equations, but rather resolves an…
I present a perturbative calculation of the spectrum of the Faddeev-Popov operator in Coulomb gauge in three dimensions, and Landau gauge in two and three dimensions, with an ansatz for the gluon propagator as the non-perturbative input.…
The issue of the BRST symmetry in presence of the Gribov horizon is addressed in Euclidean Yang-Mills theories in the Landau gauge. The positivity of the Faddeev-Popov operator within the Gribov region enables us to convert the soft…
Non-perturbative formalism of the generalized effective action is used for deriving the Schwinger-Dyson equations. In order to clear the domain of integration in the functional integral from gauge copies a restriction to the Gribov horizon…
Gribov ambiguity is a problem that arises when we try to single out the physical gauge degree of freedom in non-Abelian gauge theory by imposing the covariant gauge constraint. Unfortunately, the solution of the gauge constraint is not…
We study the Landau-gauge Gribov ghost form-factor sigma(p^2) for SU(N) Yang-Mills theories in the d-dimensional case. We find a qualitatively different behavior for d=3,4 w.r.t. d=2. In particular, considering any (sufficiently regular)…
The dependence of the gluon and ghost propagator in pure SU(3) gauge theory on the choice of Gribov copies in Landau gauge is studied. Simulations were performed on several lattice sizes at $\beta$=5.8, 6.0 and 6.2. In the infrared region…
After reviewing Gribov ambiguity of non-Abelian gauge theories, a phenomenon related to the topology of the bundle of gauge connections, we show that there is a similar feature for noncommutative QED over Moyal space, despite the structure…
In this talk we report on a recent lattice investigation of the Landau gauge gluon and ghost propagators in pure SU(3) lattice gauge theory with a special emphasis on the Gribov copy problem. In the (infrared) region of momenta $q^2 \le 0.3…
We show that an exact non-perturbative quantization of continuum gauge theory is provided by the Faddeev-Popov formula in Landau gauge, $\d(\p \cdot A) \det[-\p \cdot D(A)] \exp[-S_{\rm YM}(A)]$, restricted to the region where the…
The effect of the Gribov horizon in Euclidean $SU(2)$ gauge theory is studied. Gauge fields on the Gribov horizon yield zero modes of ghosts and anti-ghosts. We show these zero modes can produce additional ghost interactions, and the Landau…
The ghost form factor entering the Gribov no-pole condition is evaluated till the third order in the gauge fields. The resulting expression turns out to coincide with Zwanziger's horizon function implementing the restriction to the Gribov…
We prove that the Faddeev-Popov ghost dressing function in the Yang-Mills theory is non-zero and finite in the limit of vanishing momenta and hence the ghost propagator behaves like free in the deep infrared regime, within the…
Following a recent proposal by Cooper and Zwanziger we investigate via $SU(2)$ lattice simulations the effect on the Coulomb gauge propagators and on the Gribov-Zwanziger confinement mechanism of selecting the Gribov copy with the smallest…
We study the gluon and ghost propagators of SU(2) lattice Landau gauge theory and find their low-momentum behavior being sensitive to the lowest non-trivial eigenvalue (\lambda_1) of the Faddeev-Popov operator. If the gauge-fixing favors…
We study the lattice gauge boson propagator of 3D compact QED in Landau gauge at zero and non-zero temperature. Non-perturbative effects are reflected by the generation of a mass $m$, by an anomalous dimension $\alpha$ and by the photon…
Recently we reported on the infrared behavior of the Landau gauge gluon and ghost dressing functions in SU(3) Wilson lattice gluodynamics with special emphasis on the Gribov problem. Here we add an investigation of the spectral properties…
We consider Yang-Mills theories in a recently proposed family of nonlinear covariant gauges that consistently deals with the issue of Gribov ambiguities. Such gauges provide a generalization of the Curci-Ferrari-Delbourgo-Jarvis gauges…