Complex Langevin boundary terms in full QCD

TL;DR

This paper investigates boundary terms in complex Langevin simulations of full QCD at non-zero density, comparing results with reweighting methods to understand and address the sign problem.

Contribution

It provides a detailed analysis of boundary terms in CLE simulations of QCD and compares different stabilization techniques against reweighting results.

Findings

Boundary terms are significant in CLE simulations.

Reweighting results agree with CLE boundary term measurements.

Dynamic stabilization affects boundary term behavior.

Abstract

Lattice simulations of non-zero density QCD introduce the so-called sign problem (complex or negative probabilities), which invalidates importance sampling methods. To circumvent this, we use the Complex Langevin Equation (CLE), to measure the boundary terms and then compare these results with the ones gotten from reweighting, confirming the expectations from previous studies. We also investigate boundary terms in simulations using CLE with dynamic stabilization and compare this, to results calculated with reweighting.