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The complex Langevin method is a leading candidate for solving the so-called sign problem occurring in various physical situations. Its most vexing problem is that in some cases it produces `convergence to the wrong limit'. In the first…

High Energy Physics - Lattice · Physics 2015-05-27 Gert Aarts , Frank A. James , Erhard Seiler , Ion-Olimpiu Stamatescu

We discuss the problem of possible boundary terms at poles of the drift in the complex Langevin method, which spoil correctness of the method. For the simplest, however paradigmatic cases we can find complete answers. Lessons for more…

High Energy Physics - Lattice · Physics 2020-11-18 Erhard Seiler

Growth in both size and complexity of modern data challenges the applicability of traditional likelihood-based inference. Composite likelihood (CL) methods address the difficulties related to model selection and computational intractability…

Statistics Theory · Mathematics 2017-09-12 Zhendong Huang , Davide Ferrari

We discuss recent developments regarding the use of kernels in complex Langevin simulations. In particular, we outline how a kernel can be used to solve the problem of wrong convergence in a simple toy model. Since conventional correctness…

High Energy Physics - Lattice · Physics 2025-12-17 Michael Mandl , Erhard Seiler , Dénes Sexty

Real time evolution of a scalar field theory is investigated. The severe sign problem is circumvented using the Complex Langevin equation. The naive application of the method breaks down for extended real times due to the appearance of…

High Energy Physics - Lattice · Physics 2025-03-03 Daniel Alvestad , Alexander Rothkopf , Dénes Sexty

There are problems in physics and particularly in field theory which are defined by complex valued weight functions $e^{-S}$ where $S$ is a polynomial action $S: R^n \rightarrow C $. The conditions under which a convergent complex Langevin…

High Energy Physics - Lattice · Physics 2009-10-22 H. Gausterer

The complex Langevin method is a promising approach to the complex-action problem based on a fictitious time evolution of complexified dynamical variables under the influence of a Gaussian noise. Although it is known to have a restricted…

High Energy Physics - Lattice · Physics 2017-01-04 Keitaro Nagata , Jun Nishimura , Shinji Shimasaki

Monte Carlo simulation of gauge theories with a $\theta$ term is known to be extremely difficult due to the sign problem. Recently there has been major progress in solving this problem based on the idea of complexifying dynamical variables.…

High Energy Physics - Lattice · Physics 2020-05-08 Mitsuaki Hirasawa , Akira Matsumoto , Jun Nishimura , Atis Yosprakob

This review explores the Complex Langevin Method (CLM), a stochastic quantization technique designed to address the sign problem in quantum field theories with complex actions. Beginning with foundational principles, the review examines the…

High Energy Physics - Lattice · Physics 2025-04-04 Anosh Joseph , Arpith Kumar

Complementary-Label Learning (CLL) is a weakly-supervised learning problem that aims to learn a multi-class classifier from only complementary labels, which indicate a class to which an instance does not belong. Existing approaches mainly…

Machine Learning · Computer Science 2023-04-12 Wei-I Lin , Hsuan-Tien Lin

When dealing with real-world optimization problems, decision-makers usually face high levels of uncertainty associated with partial information, unknown parameters, or complex relationships between these and the problem decision variables.…

Optimization and Control · Mathematics 2023-05-01 Antonio Alcántara , Carlos Ruiz

The Caldeira-Leggett (CL) model, which describes a system bi-linearly coupled to a harmonic bath, has enjoyed popularity in condensed phase spectroscopy owing to its utmost simplicity. However, the applicability of the model to cases with…

Chemical Physics · Physics 2016-05-18 Fabian Gottwald , Sergei D. Ivanov , Oliver Kühn

In the numerical simulation of certain field theoretical models, the complex Langevin simulation has been believed to fail due to the violation of ergodicity. We give a detailed analysis of this problem based on a toy model with one degree…

High Energy Physics - Theory · Physics 2009-10-22 K. Fujimura , K. Okano , L. Schülke , K. Yamagishi , B. Zheng

The composite likelihood (CL) is amongst the computational methods used for estimation of the generalized linear mixed model (GLMM) in the context of bivariate meta-analysis of diagnostic test accuracy studies. Its advantage is that the…

Methodology · Statistics 2018-07-12 Aristidis K. Nikoloulopoulos

The real time evolution of a scalar field in 0+1 dimensions is investigated on a complex time contour. The path integral formulation of the system has a sign problem, which is circumvented using the Complex Langevin equation. Measurement of…

High Energy Physics - Lattice · Physics 2023-09-13 Nina Maria Lampl , Dénes Sexty

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

We develop an efficient sampling method by simulating Langevin dynamics with an artificial force rather than a natural force by using the gradient of the potential energy. The standard technique for sampling following the predetermined…

Statistical Mechanics · Physics 2015-09-30 M. Ohzeki , A. Ichiki

We discuss conditions under which expectation values computed from a complex Langevin process $Z$ will converge to integral averages over a given complex valued weight function. The difficulties in proving a general result are pointed out.…

High Energy Physics - Lattice · Physics 2009-10-22 H. Gausterer , Sean Lee

This paper investigates the expected excess risk of in-context learning (ICL) for multiclass classification. We formalize each task as a sequence of labeled examples followed by a query input; a pretrained model then estimates the query's…

Machine Learning · Statistics 2025-09-03 Chenrui Liu , Falong Tan , Chuanlong Xie , Yicheng Zeng , Lixing Zhu

Calibration is a frequently invoked concept when useful label probability estimates are required on top of classification accuracy. A calibrated model is a function whose values correctly reflect underlying label probabilities. Calibration…

Machine Learning · Computer Science 2024-12-03 Alireza Torabian , Ruth Urner