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Related papers: Deep Learning Beyond Lefschetz Thimbles

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Recently there has been remarkable progress in solving the sign problem, which occurs in investigating statistical systems with a complex weight. The two promising methods, the complex Langevin method and the Lefschetz thimble method, share…

High Energy Physics - Lattice · Physics 2018-04-18 Jun Nishimura , Shinji Shimasaki

Thimble regularisation of lattice field theories has been proposed as a solution to the infamous sign problem. It is conceptually very clean and powerful, but it is in practice limited by a potentially very serious issue: in general many…

High Energy Physics - Lattice · Physics 2022-06-22 Francesco Di Renzo , Kevin Zambello

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

Thimble regularization as a solution to the sign problem has been successfully put at work for a few toy models. Given the non trivial nature of the method (also from the algorithmic point of view) it is compelling to provide evidence that…

High Energy Physics - Lattice · Physics 2015-12-21 G. Eruzzi , F. Di Renzo

The tempered Lefschetz thimble method is a parallel-tempering algorithm towards solving the numerical sign problem. It uses the flow time of the gradient flow as a tempering parameter and is expected to tame both the sign and multimodal…

Strongly Correlated Electrons · Physics 2019-12-25 Masafumi Fukuma , Nobuyuki Matsumoto , Naoya Umeda

The quantum Monte Carlo method on asymptotic Lefschetz thimbles is a numerical algorithm devised specifically for alleviation of the sign problem appearing in the simulations of quantum many-body systems. In this method, the sign problem is…

Strongly Correlated Electrons · Physics 2021-10-26 Petr A. Mishchenko , Yasuyuki Kato , Yukitoshi Motome

Lefschetz thimbles have been proposed recently as a possible solution to the complex action problem (sign problem) in Monte Carlo simulations. Here we discuss pure abelian gauge theory with a complex coupling $\beta$ and apply the concept…

High Energy Physics - Lattice · Physics 2020-01-28 Jan M. Pawlowski , Manuel Scherzer , Christian Schmidt , Felix P. G. Ziegler , Felix Ziesché

We propose a new approach to circumvent the sign problem in which the integration path is optimized to control the sign problem. We give a trial function specifying the integration path in the complex plane and tune it to optimize the cost…

High Energy Physics - Lattice · Physics 2017-12-13 Yuto Mori , Kouji Kashiwa , Akira Ohnishi

The numerical sign problem has long been a major obstacle to first-principles calculations in various important fields of physics. We report that the recently proposed algorithm, tempered Lefschetz thimble method (TLTM), and its worldvolume…

High Energy Physics - Lattice · Physics 2021-11-30 Masafumi Fukuma , Nobuyuki Matsumoto

The tempered Lefschetz thimble method (TLTM) is a parallel-tempering algorithm towards solving the numerical sign problem, where the system is tempered by the antiholomorphic gradient flow to tame both the sign and ergodicity problems…

High Energy Physics - Lattice · Physics 2020-02-14 Masafumi Fukuma , Nobuyuki Matsumoto , Naoya Umeda

The sign problem that arises in Hybrid Monte Carlo calculations can be mitigated by deforming the integration manifold. While simple transformations are highly efficient for simulation, their efficacy systematically decreases with…

Disordered Systems and Neural Networks · Physics 2025-02-07 Christoph Gäntgen , Thomas Luu , Marcel Rodekamp

We consider a hybrid Monte Carlo algorithm which is applicable to lattice theories defined on Lefschetz thimbles. In the algorithm, any point (field configuration) on a thimble is parametrized uniquely by the flow-direction and the…

High Energy Physics - Lattice · Physics 2015-06-17 H. Fujii , D. Honda , M. Kato , Y. Kikukawa , S. Komatsu , T. Sano

The complex Langevin method and the generalized Lefschetz-thimble method are two closely related approaches to the sign problem, which are both based on complexification of the original dynamical variables. The former can be viewed as a…

High Energy Physics - Lattice · Physics 2017-06-28 Jun Nishimura , Shinji Shimasaki

Recently, we have proposed a novel approach (arxiv:1205.3996) to deal with the sign problem that hinders Monte Carlo simulations of many quantum field theories (QFTs). The approach consists in formulating the QFT on a Lefschetz thimble. In…

High Energy Physics - Lattice · Physics 2015-06-11 Marco Cristoforetti , Francesco Di Renzo , Luigi Scorzato

The fermion sign problem appearing in the mean-field approximation is considered, and the systematic computational scheme of the free energy is devised by using the Lefschetz-thimble method. We show that the Lefschetz-thimble method…

High Energy Physics - Theory · Physics 2015-06-03 Yuya Tanizaki , Hiromichi Nishimura , Kouji Kashiwa

We introduce the feedforward neural network to attack the sign problem via the path optimization method. The variables of integration is complexified and the integration path is optimized in the complexified space by minimizing the cost…

High Energy Physics - Lattice · Physics 2019-12-06 Yuto Mori , Kouji Kashiwa , Akira Ohnishi

The tempered Lefschetz thimble method (TLTM) is a parallel-tempering algorithm towards solving the numerical sign problem. It tames both the sign and ergodicity problems simultaneously by tempering the system with the flow time of…

High Energy Physics - Lattice · Physics 2020-01-07 Masafumi Fukuma , Nobuyuki Matsumoto , Naoya Umeda

Monte Carlo simulations of lattice quantum field theories on Lefschetz thimbles are non trivial. We discuss a new Monte Carlo algorithm based on the idea of computing contributions to the functional integral which come from complete flow…

High Energy Physics - Lattice · Physics 2016-11-28 Francesco Di Renzo , Giovanni Eruzzi

The Picard-Lefschetz theory has been attracting much attention as a tool to evaluate a multi-variable integral with a complex weight, which appears in various important problems in theoretical physics. The idea is to deform the integration…

High Energy Physics - Lattice · Physics 2022-06-10 Genki Fujisawa , Jun Nishimura , Katsuta Sakai , Atis Yosprakob

A solution to the sign problem is the so-called "Lefschetz thimble approach" where the domain of integration for field variables in the path integral is deformed from the real axis to a sub-manifold in the complex space. For properly chosen…

High Energy Physics - Lattice · Physics 2016-06-01 Andrei Alexandru , Gokce Basar , Paulo F. Bedaque , Gregory W. Ridgway , Neill C. Warrington