English
Related papers

Related papers: Practical approach to the sign problem at finite t…

200 papers

Lattice scalar field theories encounter a sign problem when the coupling constant is complex. This is a close cousin of the real-time sign problems that afflict the lattice Schwinger-Keldysh formalism, and a more distant relative of the…

High Energy Physics - Lattice · Physics 2022-12-28 Scott Lawrence , Hyunwoo Oh , Yukari Yamauchi

The Taylor expansion of thermodynamic observables at a finite baryon chemical potential $\mu_B$ is an oft-used method to circumvent the well-known sign problem of Lattice QCD. Owing to the associated difficulty and limitations of precision…

High Energy Physics - Phenomenology · Physics 2023-02-14 Sabarnya Mitra , Prasad Hegde , Christian Schmidt

We present a systematic study of the effectiveness of light quark mass reweighting. This method allows a single lattice QCD ensemble, generated with a specific value of the dynamical light quark mass, to be used to determine results for…

High Energy Physics - Lattice · Physics 2013-03-14 Qi Liu , Norman H. Christ , Chulwoo Jung

We present lattice simulations on the phase diagram of Quantum Chromodynamics (QCD) with two light quark flavours at finite chemical potential $\mu$. To circumvent the sign problem we use the complex Langevin method. In this study, we have…

High Energy Physics - Lattice · Physics 2022-03-25 Felipe Attanasio , Benjamin Jäger , Felix P. G. Ziegler

The complex Langevin method has been attracting much attention as a solution to the sign problem since the method was shown to work in finite density QCD in the deconfined phase by using the so-called gauge cooling procedure. Whether it…

High Energy Physics - Lattice · Physics 2015-11-30 Keitaro Nagata , Jun Nishimura , Shinji Shimasaki

Lattice QCD at finite baryon chemical potential has the infamous sign problem which hinders Monte Carlo simulations. This can be remedied by a dual representation that makes the sign problem mild. In the strong coupling limit, the dual…

High Energy Physics - Lattice · Physics 2022-12-07 Jangho Kim , Pratitee Pattanaik , Wolfgang Unger

The study of nuclear physics using lattice QCD is hindered by an exponentially large signal-to-noise problem which is conventionally alleviated by raising the quark masses to unphysically high values. We propose a novel form of partial…

High Energy Physics - Lattice · Physics 2010-01-12 Amy N. Nicholson

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

We make an analysis of the two-dimensional U(1) lattice gauge theory with a $\theta$ term by using the tensor renormalization group. Our numerical result for the free energy shows good consistency with the exact one at finite coupling…

High Energy Physics - Lattice · Physics 2020-05-20 Yoshinobu Kuramashi , Yusuke Yoshimura

For scalar QED on a three-dimensional toroidal lattice with a fine lattice spacing we consider the renormalization problem of choosing counter terms depending on the lattice spacing, so that the theory stays finite as the spacing goes to…

Mathematical Physics · Physics 2015-07-07 J. Dimock

Many fascinating systems suffer from a severe (complex action) sign problem preventing us from calculating them with Markov Chain Monte Carlo simulations. One promising method to alleviate the sign problem is the transformation of the…

Strongly Correlated Electrons · Physics 2022-11-18 Marcel Rodekamp , Christoph Gäntgen

Long-range interactions in finite density QCD necessitate a non-perturbative approach in order to reliably map out the key features and spectrum of the QCD phase diagram. However, the complex nature of the fermion determinant in this sector…

High Energy Physics - Lattice · Physics 2008-11-26 A. Dougall

In this letter we give the equation of state of QCD at finite temperatures and densities. The recently proposed overlap improving multi-parameter reweighting technique is used to determine observables at nonvanishing chemical potentials.…

High Energy Physics - Lattice · Physics 2008-11-26 Z. Fodor , S. D. Katz , K. K. Szabo

Lattice field theory with the $\theta$ term suffers from the sign problem. The sign problem appears as flattening of the free energy. As an alternative to the conventional method, the Fourier transform method (FTM), we apply the maximum…

High Energy Physics - Lattice · Physics 2016-09-01 Masahiro Imachi , Yasuhiko Shinno , Hiroshi Yoneyama

A nonperturbative lattice study of QCD at finite chemical potential is complicated due to the complex fermion determinant and the sign problem. Here we apply the method of stochastic quantization and complex Langevin dynamics to this…

High Energy Physics - Lattice · Physics 2009-02-09 Gert Aarts , Ion-Olimpiu Stamatescu

Finite-density QCD is difficult to study numerically because of the sign problem. We prove that, in a certain region of the phase diagram, the phase quenched approximation is exact to O(Nf/Nc). It is true for any physical observables. We…

High Energy Physics - Lattice · Physics 2012-11-06 Masanori Hanada , Yoshinori Matsuo , Naoki Yamamoto

Finite density simulations require dynamical fermions which are computationally demanding. We employ Ferrenberg and Swendsen reweighting method to reduce the number of ensembles needed. We use their method to do a combined reweighting in…

High Energy Physics - Lattice · Physics 2009-09-29 Anyi Li , Andrei Alexandru , Keh-Fei Liu

In this paper a robust second-order method is developed for the solution of strongly convex l1-regularized problems. The main aim is to make the proposed method as inexpensive as possible, while even difficult problems can be efficiently…

Optimization and Control · Mathematics 2015-01-13 Kimon Fountoulakis , Jacek Gondzio

Quantum field theories at finite matter densities generically possess a partition function that is exponentially suppressed with the volume compared to that of the phase quenched analogue. The smallness arises from an almost uniform…

High Energy Physics - Lattice · Physics 2017-08-02 Nicolas Garron , Kurt Langfeld

Monte Carlo methods cannot probe far into the QCD phase diagram with a real chemical potential, due to the famous sign problem. Complex Langevin simulations, using adaptive step-size scaling and gauge cooling, are suited for sampling path…

High Energy Physics - Lattice · Physics 2015-11-02 Gert Aarts , Felipe Attanasio , Benjamin Jäger , Erhard Seiler , Dénes Sexty , Ion-Olimpiu Stamatescu