Kernels and integration cycles in complex Langevin simulations

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Mandl, Michael, Hansen, Michael W., Seiler, Erhard, Sexty, Dénes
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866909353377792000
author Mandl, Michael
Hansen, Michael W.
Seiler, Erhard
Sexty, Dénes
author_facet Mandl, Michael
Hansen, Michael W.
Seiler, Erhard
Sexty, Dénes
contents The method of complex Langevin simulations is a tool that can be used to tackle the complex-action problem encountered, for instance, in finite-density lattice quantum chromodynamics or real-time lattice field theories. The method is based on a stochastic evolution of the dynamical degrees of freedom via (complex) Langevin equations, which, however, sometimes converge to the wrong equilibrium distributions. While the convergence properties of the evolution can to some extent be assessed by studying so-called boundary terms, we demonstrate in this contribution that boundary terms on their own are not sufficient as a correctness criterion. Indeed, in their absence complex Langevin simulation results might still be spoiled by unwanted so-called integration cycles. In particular, we elaborate on how the introduction of a kernel into the complex Langevin equation can - in principle - be used to control which integration cycles are sampled in a simulation such that correct convergence is restored.
format Preprint
id arxiv_https___arxiv_org_abs_2410_13423
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Kernels and integration cycles in complex Langevin simulations
Mandl, Michael
Hansen, Michael W.
Seiler, Erhard
Sexty, Dénes
High Energy Physics - Lattice
High Energy Physics - Theory
The method of complex Langevin simulations is a tool that can be used to tackle the complex-action problem encountered, for instance, in finite-density lattice quantum chromodynamics or real-time lattice field theories. The method is based on a stochastic evolution of the dynamical degrees of freedom via (complex) Langevin equations, which, however, sometimes converge to the wrong equilibrium distributions. While the convergence properties of the evolution can to some extent be assessed by studying so-called boundary terms, we demonstrate in this contribution that boundary terms on their own are not sufficient as a correctness criterion. Indeed, in their absence complex Langevin simulation results might still be spoiled by unwanted so-called integration cycles. In particular, we elaborate on how the introduction of a kernel into the complex Langevin equation can - in principle - be used to control which integration cycles are sampled in a simulation such that correct convergence is restored.
title Kernels and integration cycles in complex Langevin simulations
topic High Energy Physics - Lattice
High Energy Physics - Theory
url https://arxiv.org/abs/2410.13423