Michael Mueller-Preussker

arXiv2010

Ergodic SO(3), monopole condensation and vortex free energy

We study the continuum limit of adjoint SU(2) LGT by means of a suppression term for Z2 monopoles. High barriers for tunnelling among different twist sectors are overcome through parallel tempering. Monopole condensation is used to study the deconfinement transition and the properties of the confined phase. Ergodicity in summing over all twist sectors allows an unbiased measure of the 't Hooft vortices free energy. Its behaviour in the SO(3) confined phase hints at differences from what conjectured for semi-integer discretizations.

hep-lat↗

arXiv2008

Coulomb gauge studies of SU(3) Yang-Mills theory on the lattice

We study the infrared behaviour of lattice SU(3) Yang-Mills theory in Coulomb gauge in terms of the ghost propagator, the Coulomb potential and the transversal and the time-time component of the equal-time gluon propagator. In particular, we focus on the Gribov problem and its impact on the observables. We observe that the simulated annealing method is advantageous for fixing the Coulomb gauge in large volumes. We study finite size and discretization effects. While finite size effects can be controlled by the cone cut, and the ghost propagator and the Coulomb potential become scaling functions with the cylinder cut, the equal-time gluon propagator does not show scaling in the considered range of the inverse coupling constant. The ghost propagator is infrared enhanced. The Coulomb potential is now extended to considerably lower momenta and shows a more complicated infrared regime. The Coulomb string tension satisfies Zwanziger's inequality, but its estimate can be considered only preliminary because of the systematic Gribov effect that is particularly strong for the Coulomb potential.

hep-lat↗