A regulated zero-temperature construction of the Fundamental Modular Region in pure Yang--Mills theory and QCD
arXiv:2607.27896
The paper defines the Fundamental Modular Region (FMR) as the zero‑temperature limit of regulated copy‑weighted Landau gauges, providing a computational method to realize absolute Landau gauge and extending the construction to full QCD with a Hamiltonian interpretation.
Abstract
We formulate the Fundamental Modular Region (FMR) as the zero-temperature limit of regulated copy-weighted Landau gauges. At finite $β$, the measure localizes on absolute minima, and the leading correction is dominated by the inverse Faddeev--Popov (FP) operator. A small $SU(2)$ benchmark provides a computational realization through population annealing and collective basin hopping. Our construction defines absolute Landau gauge without parametrizing the FMR boundary and extends naturally to full quantum chromodynamics (QCD). It also admits a Hamiltonian interpretation in terms of the gauge-fixed vacuum wave functional on the FMR.
18 pages, 2 figures, 1 table