Reweighted complex Langevin and its application to two-dimensional QCD

TL;DR

This paper introduces a reweighted complex Langevin method that extends the applicability of complex Langevin simulations to complex actions, demonstrated on two-dimensional QCD at nonzero chemical potential.

Contribution

The paper proposes a novel reweighting approach for complex Langevin simulations, enabling exploration of parameter regions previously inaccessible.

Findings

Successfully applied to two-dimensional QCD at nonzero chemical potential

Enables access to new parameter regions beyond standard complex Langevin capabilities

Validates the method's effectiveness in complex action scenarios

Abstract

We present the reweighted complex Langevin method, which enlarges the applicability range of the complex Langevin method by reweighting the complex trajectories. In this reweighting procedure both the auxiliary and target ensembles have a complex action. We validate the method by applying it to two-dimensional strong-coupling QCD at nonzero chemical potential, and observe that it gives access to parameter regions that could otherwise not be reached with the complex Langevin method.