Lattice Landau gauge gluon propagator at finite temperature: non-zero Matsubara frequencies and spectral densities

TL;DR

This paper computes the finite-temperature lattice Landau gauge gluon propagator including non-zero Matsubara frequencies, and reconstructs its spectral density to explore implications for gluon confinement.

Contribution

It introduces a method to include non-zero Matsubara frequencies in lattice calculations and reconstructs spectral densities using Tikhonov regularisation, advancing understanding of gluon confinement at finite temperature.

Findings

Spectral densities obtained via Tikhonov regularisation.

Implications for gluon confinement discussed.

Finite-temperature effects on gluon propagator analyzed.

Abstract

The lattice Landau gauge gluon propagator at finite temperature is computed including the non-zero Matsubara frequencies. Furthermore, the K\"all\'en-Lehmann representation is inverted and the corresponding spectral density evaluated using a Tikhonov regularisation together with the Morozov discrepancy principle. Implications for gluon confinement are discussed.