Positivity of center subsets for QCD

Abstract

We further pursue an approach to the sign problem of quantum chromodynamics at nonzero chemical potential, in which configurations of the lattice path integral are gathered into subsets. In the subset construction we multiply each temporal link by center elements independently and in a first step neglect the gauge action. The positivity of the subset weights -- shown for 0+1 dimensions in an earlier study -- extends to larger lattices: for two sites in the temporal direction and arbitrary spatial extent we give a proof of the positivity by decomposing the subset weight in positive summands. From numerical evidence we conjecture that the positivity persists on larger lattices and that the gauge action can be reintroduced through mild reweighting. First results on the quark number obtained with this method in two dimensions are shown as well.

13 pages, 2 figures, as published in Phys. Rev. D

References in corpus (3)

• The phase diagram of a gauge theory with fermionic baryons
• QCD in One Dimension at Nonzero Chemical Potential
• Subsets and the canonical partition functions

Cited by in corpus (5)

• Understanding of QCD at high density from Z3-symmetric QCD-like theory
• Interplay between sign problem and Z_3 symmetry in three-dimensional Potts model
• Sign problem in $Z_3$-symmetric effective Polyakov-line model
• Solution of the sign problem in the Potts model at fixed fermion number
• Diagrammatic representation of scalar QCD and sign problem at nonzero chemical potential