Lefschetz thimble-inspired weight regularizations for complex Langevin simulations

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Boguslavski, Kirill, Hotzy, Paul, Müller, David I.
Natura: Preprint
Pubblicazione: 2024
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866909546763517952
author Boguslavski, Kirill
Hotzy, Paul
Müller, David I.
author_facet Boguslavski, Kirill
Hotzy, Paul
Müller, David I.
contents Complex Langevin (CL) is a computational method to circumvent the numerical sign problem with applications in finite-density quantum chromodynamics and the real-time dynamics of quantum field theories. It has long been known that, depending on the simulated system, CL does not always converge correctly. In this work, we provide numerical evidence that the success or failure of the complex Langevin method is deeply tied to the Lefschetz thimble structure of the simulated system. This is demonstrated by constructing weight function regularizations that deform the thimbles of systems with compact domains. Our results indicate that CL converges correctly when the regularized system exhibits a single relevant compact thimble. We introduce a bias correction to retrieve the values of the original theory for parameter sets where a direct complex Langevin approach fails. The effectiveness of this method is illustrated using several toy models, including the cosine model and the SU(2) and SU(3) Polyakov chains. Finally, we discuss the opportunities and limitations of this regularization approach for lattice field theories.
format Preprint
id arxiv_https___arxiv_org_abs_2412_02396
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Lefschetz thimble-inspired weight regularizations for complex Langevin simulations
Boguslavski, Kirill
Hotzy, Paul
Müller, David I.
High Energy Physics - Lattice
High Energy Physics - Phenomenology
Complex Langevin (CL) is a computational method to circumvent the numerical sign problem with applications in finite-density quantum chromodynamics and the real-time dynamics of quantum field theories. It has long been known that, depending on the simulated system, CL does not always converge correctly. In this work, we provide numerical evidence that the success or failure of the complex Langevin method is deeply tied to the Lefschetz thimble structure of the simulated system. This is demonstrated by constructing weight function regularizations that deform the thimbles of systems with compact domains. Our results indicate that CL converges correctly when the regularized system exhibits a single relevant compact thimble. We introduce a bias correction to retrieve the values of the original theory for parameter sets where a direct complex Langevin approach fails. The effectiveness of this method is illustrated using several toy models, including the cosine model and the SU(2) and SU(3) Polyakov chains. Finally, we discuss the opportunities and limitations of this regularization approach for lattice field theories.
title Lefschetz thimble-inspired weight regularizations for complex Langevin simulations
topic High Energy Physics - Lattice
High Energy Physics - Phenomenology
url https://arxiv.org/abs/2412.02396