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Related papers: Stabilising complex Langevin simulations

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We demonstrate analytically that complex Langevin dynamics can solve the sign problem in one-dimensional QCD in the thermodynamic limit. In particular, it is shown that the contributions from the complex and highly oscillating spectral…

High Energy Physics - Lattice · Physics 2014-11-21 Gert Aarts , K. Splittorff

We study the Stephanov model, which is an RMT model for QCD at finite density, using the Complex Langevin algorithm. Naive implementation of the algorithm shows convergence towards the phase quenched or quenched theory rather than to…

High Energy Physics - Lattice · Physics 2018-04-18 Jacques Bloch , Jonas Glesaaen , Jacobus Verbaarschot , Savvas Zafeiropoulos

We present our results obtained from gauge cooled complex Langevin simulations in 1+1d QCD at non-zero densities in the strong coupling regime with unrooted staggered fermions. For small quark masses there are regions of the chemical…

High Energy Physics - Lattice · Physics 2016-11-03 Sebastian Schmalzbauer , Jacques Bloch

The sign problem of QCD prevents standard lattice simulations to determine the phase diagram of strong interactions with a finite chemical potential directly. Complex Langevin simulations provide an alternative method to sample path…

High Energy Physics - Lattice · Physics 2015-06-09 Gert Aarts , Felipe Attanasio , Benjamin Jäger , Erhard Seiler , Dénes Sexty , Ion-Olimpiu Stamatescu

We simulate lattice QCD at finite quark-number chemical potential, $\mu$, using the complex-Langevin equation (CLE) with gauge-cooling and adaptive updating to prevent instabilities. The CLE is used because QCD at finite $\mu$ has a complex…

High Energy Physics - Lattice · Physics 2018-10-30 D. K. Sinclair , J. B. Kogut

This study explores the potential of modern implicit solvers for stochastic partial differential equations in the simulation of real-time complex Langevin dynamics. Not only do these methods offer asymptotic stability, rendering the issue…

High Energy Physics - Lattice · Physics 2021-09-15 Daniel Alvestad , Rasmus Larsen , Alexander Rothkopf

Complex Langevin dynamics can be used to perform numerical simulations of theories with a complex action. In order to justify the procedure, it is important to understand the properties of the real and positive distribution, which is…

High Energy Physics - Lattice · Physics 2013-09-13 Pietro Giudice , Gert Aarts , Erhard Seiler

It is well known that investigating QCD at finite density by standard Monte Carlo methods is extremely difficult due to the sign problem. Some years ago, the complex Langevin method with gauge cooling was shown to work at high temperature,…

High Energy Physics - Lattice · Physics 2019-01-15 Keitaro Nagata , Jun Nishimura , Shinji Shimasaki

Underdamped Langevin dynamics (ULD) is a widely-used sampler for Gibbs distributions $\pi\propto e^{-V}$, and is often empirically effective in high dimensions. However, existing non-asymptotic convergence guarantees for discretized ULD…

Machine Learning · Computer Science 2026-03-04 Shiyuan Zhang , Qiwei Di , Xuheng Li , Quanquan Gu

I report large-scale Monte Carlo studies of a one-dimensional height-restricted stochastic sandpile using the quasistationary simulation method. Results for systems of up to 50 000 sites yield estimates for critical exponents that differ…

Statistical Mechanics · Physics 2007-05-23 Ronald Dickman

The sign problem at nonzero chemical potential prohibits the use of importance sampling in lattice simulations. Since complex Langevin dynamics does not rely on importance sampling, it provides a potential solution. Recently it was shown…

High Energy Physics - Lattice · Physics 2015-06-12 Gert Aarts , Frank A. James , Jan M. Pawlowski , Erhard Seiler , Denes Sexty , Ion-Olimpiu Stamatescu

We consider the existence of a dynamically stable soliton in the one-dimensional cubic-quintic nonlinear Schr\"odinger model with strong cubic nonlinearity management for periodic and random modulations. We show that the predictions of the…

Other Condensed Matter · Physics 2015-06-25 Fatkhulla Kh. Abdullaev , Josselin Garnier

The complex Langevin method is one hopeful candidate to tackle the sign problem. This method is applicable not only to QCD but also to nonrelativistic field theory, such as condensed matter physics. We present the simulation results of a…

High Energy Physics - Lattice · Physics 2015-08-04 Arata Yamamoto , Tomoya Hayata

The complex Langevin (CL) method is a promising approach to overcome the sign problem that occurs in real-time formulations of quantum field theories. Using the Schwinger-Keldysh formalism, we study SU($N_c$) gauge theories with CL. We…

High Energy Physics - Lattice · Physics 2023-06-13 Kirill Boguslavski , Paul Hotzy , David I. Müller

This article deals with the realisation of constraints in underdamped Langevin dynamics via soft-constrained dynamics. Specifically, we study systems with a large (or small) parameter that controls the constraint mechanisms, e.g. the…

Probability · Mathematics 2026-04-03 Carsten Hartmann , Lara Neureither , Upanshu Sharma

We simulate lattice QCD at finite quark-number chemical potential to study nuclear matter, using the complex Langevin equation (CLE). The CLE is used because the fermion determinant is complex so that standard methods relying on importance…

High Energy Physics - Lattice · Physics 2018-04-18 D. K. Sinclair , J. B. Kogut

The three-dimensional SU(3) spin model is an effective Polyakov loop model for QCD at nonzero temperature and density. It suffers from a sign problem at nonzero chemical potential. We revisit this model using complex Langevin dynamics and…

High Energy Physics - Lattice · Physics 2015-06-03 Gert Aarts , Frank A. James

We study lattice QCD with two flavors of dynamical domain wall quarks. With renormalization group motivated actions, we find chiral symmetry can be preserved to a high degree at lattice cut off of a^{-1} \sim 2 GeV even for fifth dimension…

High Energy Physics - Lattice · Physics 2015-06-25 Taku Izubuchi , RBC Collaboration

In stochastic quantisation, quantum mechanical expectation values are computed as averages over the time history of a stochastic process described by a Langevin equation. Complex stochastic quantisation, though theoretically not rigorously…

High Energy Physics - Lattice · Physics 2014-08-18 Amel Durakovic , Emil Cortes Andre , Anders Tranberg

In recent years there has been much progress on the investigation of the QCD phase diagram with lattice QCD simulations. In this review I focus on the developments in the last two years. Especially the addition of external influences or new…

High Energy Physics - Lattice · Physics 2021-02-17 Jana N. Guenther