Related papers: Asymptotic Limits and Sum Rules for Propagators in…
We summarize the current status of our numerical results for the gluon and ghost propagators and for the Kugo-Ojima confinement parameter in quenched SU(3) lattice Landau gauge theory. The data for the propagators are compared to our…
The coupled Dyson-Schwinger equations for the gluon and ghost propagators are investigated in the Landau gauge using a two-loop improved truncation that preserves the multiplicative renormalizability of the propagators. In this truncation…
The infrared features of Landau gauge QCD are studied by the lattice simulation of $\beta=6.0, 16^4, 24^4, 32^4$ and $\beta=6.4, 32^4, 48^4$. We adopt two definitions of the gauge field; 1) $U-$linear 2) $\log U$ and measured the gluon…
We compute the gluon and ghost propagators of Yang-Mills theory in linear covariant gauges from the coupled system of Dyson-Schwinger equations. For small values of the gauge fixing parameter $\xi\sim 0.1$, the deviations to the Landau…
We study the long-distance properties of quantum chromodynamics in an expansion in powers of the three-gluon, four-gluon, and ghost-gluon couplings, but without expanding in the quark-gluon coupling. This is motivated by two observations.…
The asymptotic behavior as t\to\infty and r\to\infty of the hard-thermal-loop propagator D^{\mu\nu}(t,r) is computed in the Coulomb gauge. The asymptotic falloff is always a power law though generally different in the deep time-like and…
We derive some exact bounds on the free energy W(J) in an SU(N) gauge theory, where J_mu^b is a source for the gluon field A_mu^b in the minimal Landau gauge, and W(J) is the generating functional of connected correlators, exp W(J) =…
Non-Abelian gauge theories with fermions transforming in the adjoint representation of the gauge group (AdjQCD) are a fundamental ingredient of many models that describe the physics beyond the Standard Model. Two relevant examples are N=1…
The gluon propagator is calculated in quenched QCD for two different lattice sizes (16^3x48 and 32^3x64) at beta=6.0. The volume dependence of the propagator in Landau gauge is studied. The smaller lattice is instrumental in revealing…
Although gauge-boson propagators in asymptotically-free gauge theories satisfy a dispersion relation, they do not satisfy the K\"allen-Lehmann (KL) representation because the spectral function changes sign. We argue that this is a simple…
We report on the infrared limit of the quenched lattice Landau gauge gluon and ghost propagators as well as the strong coupling constant computed from large asymmetric lattices. The infrared lattice propagators are compared with the pure…
Both lattice simulations and theoretical studies show that the spectral function of the gluon propagator of QCD (in various gauges, as well as for the gauge-invariant Pinch Technique, or PT, propagator) is not non-negative everywhere,…
We summarize the higher-loop perturbative computation of the ghost and gluon propagators in SU(3) Lattice Gauge Theory. Our final aim is to compare with results from lattice simulations in order to expose the genuinely non-perturbative…
Using the Dyson-Schwinger approach we investigate Landau gauge QCD with a relatively large number of chiral quark flavours. A self-consistent treatment on the propagator level enables us to study unquenching effects via the quark loop…
We reconstruct the gluon spectral function in Landau gauge QCD from numerical data for the gluon propagator. The reconstruction relies on two novel ingredients: Firstly we derive analytically the low frequency asymptotics of the spectral…
We discuss a non-perturbative lattice calculation of the ghost and gluon propagators in the pure Yang-Mills theory in Landau gauge. The ultraviolet behaviour is checked up to NNNLO yielding the value…
Quarks in the adjoint representation have been a subject of study for both conceptual and practical purposes. Conceptually, their differences when it comes to confining and chiral symmetry properties has long been suspected to hold…
The Kugo-Ojima confinement criterion and its relation to the infrared behaviour of the gluon and ghost propagators in Landau gauge QCD are reviewed. The realization of this confinement criterion (which in Landau gauge relates to Zwanziger's…
With the aim of looking for signatures of deconfinement, the poles and the spectral function of the Landau-gauge gluon propagator are investigated at one loop, vanishing spatial momentum and finite temperature within the framework of the…
We present recent results of the Landau gauge gluon and ghost propagators in SU(3) pure gauge theory at Wilson \beta=5.7 for lattice sizes up to 80^4 corresponding to physical volumes up to (13.2 fm)^4. In particular, we focus on…