English
Related papers

Related papers: Complex Langevin boundary terms in full QCD

200 papers

In complex Langevin simulations, the insufficient decay of the probability density near infinity leads to boundary terms that spoil the formal argument for correctness. We present a formulation of this term that is cheaply measurable in…

High Energy Physics - Lattice · Physics 2021-12-07 Michael W. Hansen , Erhard Seiler , Dénes Sexty , Ion-Olimipu Stamatescu

As is well known the Complex Langevin (CL) method sometimes fails to converge or converges to the wrong limit. We identified one reason for this long ago: insufficient decay of the probability density either near infinity or near poles of…

High Energy Physics - Lattice · Physics 2019-01-30 Manuel Scherzer , Erhard Seiler , Dénes Sexty , Ion-Olimpiu Stamatescu

One reason for the well known fact that the Complex Langevin (CL) method sometimes fails to converge or converges to the wrong limit has been identified long ago: it is insufficient decay of the probability density either near infinity or…

High Energy Physics - Lattice · Physics 2020-01-15 M. Scherzer , E. Seiler , D. Sexty , I. -O. Stamatescu

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

QCD at finite quark-/baryon-number density, which describes nuclear matter, has a sign problem which prevents direct application of standard simulation methods based on importance sampling. When such finite density is implemented by the…

High Energy Physics - Lattice · Physics 2016-11-09 D. K. Sinclair , J. B. Kogut

The Complex Langevin (CL) method to simulate `complex probabilities', ideally produces expectation values for the observables that converge to a limit equal to the expectation values obtained with the original complex `probability' measure.…

High Energy Physics - Lattice · Physics 2023-12-01 Erhard Seiler , Dénes Sexty , Ion-Olimpiu Stamatescu

We study the use of the complex-Langevin equation (CLE) to simulate lattice QCD at a finite chemical potential ($\mu$) for quark-number, which has a complex fermion determinant that prevents the use of standard simulation methods based on…

High Energy Physics - Lattice · Physics 2019-10-02 J. B. Kogut , D. K. Sinclair

Recent progress of the complex Langevin method and the Lefschetz thimble in connection with the sign problem is reviewed. These methods rely on the complexification of the original field manifold and they allow direct simulations of…

High Energy Physics - Lattice · Physics 2014-12-01 Denes Sexty

Some recent developments to handle the numerical sign problem in QCD and related theories at nonzero density are reviewed. In this contribution I focus on changing the integration order to soften the severity of the sign problem, the…

High Energy Physics - Lattice · Physics 2015-02-13 Gert Aarts

The sign problem appears in lattice QCD as soon as a non-zero chemical potential is introduced. This prevents direct simulations to determine the phase structure of the strongly interacting matter. Complex Langevin methods have been…

High Energy Physics - Lattice · Physics 2018-04-18 Felipe Attanasio , Benjamin Jäger

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

Although the complex Langevin method can solve the sign problem in simulations of theories with complex actions, the method will yield the wrong results if known validity conditions are not satisfied. We present a novel method to compute…

High Energy Physics - Lattice · Physics 2017-04-05 Jacques Bloch

Complex Langevin simulations provide an alternative to sample path integrals with complex weights and therefore are suited to determine the phase diagram of QCD from first principles. We use our proposed method of Dynamic Stabilisation (DS)…

High Energy Physics - Lattice · Physics 2016-07-20 Gert Aarts , Felipe Attanasio , Benjamin Jäger , Dénes Sexty

Complex Langevin simulations have been able to successfully reproduce results from Monte Carlo methods in the region where the sign problem is mild and make predictions when it is exponentially hard. We present here our study of the QCD…

High Energy Physics - Lattice · Physics 2016-10-25 Gert Aarts , Felipe Attanasio , Benjamin Jäger , Dénes Sexty

Progress in the application of the complex Langevin method to full QCD at non-zero chemical potential is reported. The method evades the sign problem which makes naive simulations at nonzero density impossible. The procedure 'gauge cooling'…

High Energy Physics - Lattice · Physics 2015-06-22 Denes Sexty

In this review we present the current state-of-the-art on complex Langevin simulations and their implications for the QCD phase diagram. After a short summary of the complex Langevin method, we present and discuss recent developments. Here…

High Energy Physics - Lattice · Physics 2020-10-28 Felipe Attanasio , Benjamin Jäger , Felix P. G. Ziegler

I review the presence of the sign problem in lattice QCD at nonzero baryon density and its relation with the overlap and Silver Blaze problems. I then discuss progress in some cases where the sign problem can be handled, either because the…

High Energy Physics - Lattice · Physics 2013-03-05 Gert Aarts

Simulations of full QCD at nonzero baryon density using light quark masses are presented. The sign problem is evaded by the usage of the complex Langevin equation. The simulations are stabilized by the gauge cooling procedure for small…

High Energy Physics - Lattice · Physics 2013-10-24 Denes Sexty

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…

High Energy Physics - Lattice · Physics 2025-03-24 Kirill Boguslavski , Paul Hotzy , David I. Müller
‹ Prev 1 2 3 10 Next ›