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Path integral Monte Carlo with Green's function analysis allows the sampling of quantum mechanical properties of molecules at finite temperature. While a high-precision computation of the energy of the Born-Oppenheimer surface from path…

Quantum Physics · Physics 2007-05-23 Daejin Shin , Ming-Chak Ho , J. Shumway

Several widely used methods for the calculation of band structures and photo emission spectra, such as the GW approximation, rely on Many-Body Perturbation Theory. They can be obtained by iterating a set of functional differential equations…

Strongly Correlated Electrons · Physics 2012-01-31 Giovanna Lani , Pina Romaniello , Lucia Reining

We present an efficient implementation of a surface Green's-function method for atomistic modeling of surfaces within the framework of density functional theory using a pseudopotential localized basis set approach. In this method, the…

Machine learning methods are applied to finding the Green's function of the Anderson impurity model, a basic model system of quantum many-body condensed-matter physics. Different methods of parametrizing the Green's function are…

Strongly Correlated Electrons · Physics 2015-06-22 Louis-François Arsenault , Alejandro Lopez-Bezanilla , O. Anatole von Lilienfeld , Andrew J. Millis

We present a method to considerably improve the numerical performance for solving Eliashberg-type coupled equations on the imaginary axis. Instead of the standard practice of introducing a hard numerical cutoff for treating the infinite…

Superconductivity · Physics 2019-05-22 Fabian Schrodi , Alex Aperis , Peter M. Oppeneer

A classical problem in acoustic (and electromagnetic) scattering concerns the evaluation of the Green's function for the Helmholtz equation subject to impedance boundary conditions on a half-space. The two principal approaches used for…

Numerical Analysis · Mathematics 2012-11-28 Michael O'Neil , Leslie Greengard , Andras Pataki

Regression with sparse inputs is a common theme for large scale models. Optimizing the underlying linear algebra for sparse inputs allows such models to be estimated faster. At the same time, centering the inputs has benefits in improving…

Computation · Statistics 2019-10-30 Jeffrey Wong

The ill-posed analytic continuation problem for Green's functions or self-energies can be done using the Pad\'e rational polynomial approximation. However, to extract accurate results from this approximation, high precision input data of…

Strongly Correlated Electrons · Physics 2017-06-28 Xing-Jie Han , Hai-Jun Liao , Hai-Dong Xie , Rui-Zhen Huang , Zi Yang Meng , Tao Xiang

Analytic continuation (AC) from the imaginary-time Green's function to the spectral function is a crucial process for numerical studies of the dynamical properties of quantum many-body systems. This process, however, is an ill-posed…

Strongly Correlated Electrons · Physics 2022-01-26 Yuichi Motoyama , Kazuyoshi Yoshimi , Junya Otsuki

We present results for many-body perturbation theory for the one-body Green's function at finite temperatures using the Matsubara formalism. Our method relies on the accurate representation of the single-particle states in standard Gaussian…

Strongly Correlated Electrons · Physics 2018-04-04 Michael Schüler , Yaroslav Pavlyukh

The goal of this paper is to achieve a computational model and corresponding efficient algorithm for obtaining a sparse representation of the fitting surface to the given scattered data. The basic idea of the model is to utilize the…

Numerical Analysis · Mathematics 2017-04-27 Yong-Xia Hao , Chong-Jun Li , Ren-Hong Wang

We present an original multi-state projective diabatization scheme based on the Green's function formalism that allows the systematic mapping of many-body ab initio calculations onto effective excitonic models. This method inherits the…

Chemical Physics · Physics 2024-08-07 Mauricio Rodríguez-Mayorga , Xavier Blase , Ivan Duchemin , Gabriele D'Avino

Reliably reconstructing physical fields from sparse sensor data is a challenge that frequently arises in many scientific domains. In practice, the process generating the data often is not understood to sufficient accuracy. Therefore, there…

Machine Learning · Computer Science 2024-01-23 Xihaier Luo , Wei Xu , Yihui Ren , Shinjae Yoo , Balu Nadiga

The image-source method is widely applied to compute room impulse responses (RIRs) of shoebox rooms with arbitrary absorption. However, with increasing RIR lengths, the number of image sources grows rapidly, leading to slow computation. In…

Audio and Speech Processing · Electrical Eng. & Systems 2023-10-12 Sebastian J. Schlecht , Karolina Prawda , Rudolf Rabenstein , Maximilian Schäfer

An end-to-end strategy for hybrid quantum-classical computations of Green's functions in many-body systems is presented and applied to the pairing model. The scheme makes explicit use of the spectral representation of the Green's function,…

Nuclear Theory · Physics 2026-05-01 Samuel Aychet-Claisse , Denis Lacroix , Vittorio Somà , Jing Zhang

Here is proposed a general subgraph-based method for efficiently sampling certain graphical models, typically using subgraphs of a fixed treewidth, and also a related method for finding minimum energy (ground) states. In the case of models…

Statistical Mechanics · Physics 2014-09-16 Alex Selby

A review of electronic dynamics of single-impurity and many-impurity Anderson models is contained in this report. Those models are used widely for many of the applications in diverse fields of interest, such as surface physics, theory of…

Strongly Correlated Electrons · Physics 2015-03-04 A. L. Kuzemsky

A surface integral equation solver is proposed for fast and accurate simulation of interconnects embedded in stratified media. A novel technique for efficient computation of the multilayer Green's function is proposed. Using the Taylor…

Computational Physics · Physics 2019-03-11 Shashwat Sharma , Utkarsh R. Patel , Sean V. Hum , Piero Triverio

We present a data-driven approach to mathematically model physical systems whose governing partial differential equations are unknown, by learning their associated Green's function. The subject systems are observed by collecting…

Numerical Analysis · Mathematics 2023-03-13 Harshwardhan Praveen , Nicolas Boulle , Christopher Earls

MR image sparsity/compressibility has been widely exploited for imaging acceleration with the development of compressed sensing. A sparsity-based approach to rigid-body motion correction is presented for the first time in this paper. A…

Computer Vision and Pattern Recognition · Computer Science 2013-02-04 Zai Yang , Cishen Zhang , Lihua Xie