Subset method for one-dimensional QCD

TL;DR

This paper introduces a subset method that effectively addresses the sign problem in one-dimensional QCD with nonzero chemical potential, demonstrating its effectiveness for up to five flavors and proposing extensions for more flavors.

Contribution

The paper presents a novel subset approach based on center symmetry that solves the sign problem in 0+1 dimensional QCD for multiple quark flavors, including extensions for larger flavor numbers.

Findings

Sign problem is solved for 1-5 flavors using the subset method.

The sign problem reappears slowly as the number of flavors increases.

Extensions of the subset method can address larger flavor numbers.

Abstract

We present a subset method which solves the sign problem for QCD at nonzero quark chemical potential in 0+1 dimensions. The subsets gather gauge configurations based on the center symmetry of the SU(3) group. We show that the sign problem is solved for one to five quark flavors and that it slowly reappears for a larger number of flavors. We formulate an extension of the center subsets that solves the sign problem for a larger number of flavors as well. We also derive some new analytical results for this toy model.