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In this paper a local Fourier analysis for multigrid methods on tetrahedral grids is presented. Different smoothers for the discretization of the Laplace operator by linear finite elements on such grids are analyzed. A four-color smoother…

Numerical Analysis · Computer Science 2014-10-28 B. Gmeiner , T. Gradl , F. Gaspar , U. Rüde

We present a comprehensive study for common second order PDE's in two dimensional disk-like systems and show how their solution can be approximated by finding the Green function of an effective one dimensional system. After elaborating on…

Computational Physics · Physics 2020-10-06 Alejandro Ferrero , Juan Pablo Mallarino

We introduce a general scheme to consistently truncate equations of motion for Green's functions. Our scheme is guaranteed to generate physical Green's functions with real excitation energies and positive spectral weights. There are free…

Strongly Correlated Electrons · Physics 2021-02-24 Francesco Catalano , Johan Nilsson

A new approximation method for inverting the Poisson's equation is presented for a continuously distributed and finite-sized source in an unbound domain. The advantage of this image multipole method arises from its ability to place the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 James H. H. Chan , Tzihong Chiueh

Flexible boundary condition methods couple an isolated defect to bulk through the bulk lattice Green's function. The inversion of the force-constant matrix for the lattice Green's function requires Fourier techniques to project out the…

Materials Science · Physics 2010-05-28 M. Ghazisaeidi , D. R. Trinkle

In this work, we investigate direction finding in the presence of sensor gain uncertainties and directional perturbations for sensor array processing in a multi-frequency scenario. Specifically, we adopt a distributed optimization scheme in…

Signal Processing · Electrical Eng. & Systems 2020-02-27 Martin Brossard , Virginie Ollier , Mohammed Nabil El Korso , Rémy Boyer , Pascal Larzabal

Fourier methods well known in signal processing are applied to three-dimensional wave propagation problems. The Fourier transform of the Green function, when written explicitly in terms of a real-valued spatial frequency, consists of…

Optics · Physics 2014-01-21 Colin J. R. Sheppard , Shan Shan Kou , Jiao Lin

We derive closed-form expressions for the poles and zeros of approximate fractional integrator/differentiator filters, which correspond to spectral roll-off filters having any desired log-log slope to a controllable degree of accuracy over…

Computational Engineering, Finance, and Science · Computer Science 2016-06-21 Julius Orion Smith , Harrison Freeman Smith

We combine the recently developed many-body Green's function theory for electrons and nuclei with the exact factorization of the wave function. The existing Born-Oppenheimer Green's functions are shown to be special cases of our exact…

Other Condensed Matter · Physics 2022-11-23 Ville J. Härkönen

Kernels are key in machine learning for modeling interactions. Unfortunately, brute-force computation of the related kernel sums scales quadratically with the number of samples. Recent Fourier-slicing methods lead to an improved linear…

Numerical Analysis · Mathematics 2025-10-14 Nicolaj Rux , Johannes Hertrich , Sebastian Neumayer

In this paper we generalize an explicit numerical scheme for the CIR process that we have proposed before. The advantage of the new proposed scheme is that preserves positivity and is well posed for a (little bit) broader set of parameters…

Numerical Analysis · Mathematics 2015-02-20 Nikolaos Halidias

The use of reduced and mixed precision computing has gained increasing attention in high-performance computing (HPC) as a means to improve computational efficiency, particularly on modern hardware architectures like GPUs. In this work, we…

Computational Engineering, Finance, and Science · Computer Science 2025-05-28 Bálint Siklósi , Pushpender K. Sharma , David J. Lusher , István Z. Reguly , Neil D. Sandham

In this note, I would like to discuss an approach to the construction of Green's function on algebraic surfaces, indicated by Manin, towards the computation of the Green's function on surfaces using Schottky uniformization. We shall see…

Geometric Topology · Mathematics 2023-08-29 Ilyas Bayramov

Traditionally, classical numerical schemes have been employed to solve partial differential equations (PDEs) using computational methods. Recently, neural network-based methods have emerged. Despite these advancements, neural network-based…

Numerical Analysis · Mathematics 2024-05-14 Taeyoung Kim , Myungjoo Kang

We describe the following new features which significantly enhance the power of the recently developed real-space imaginary-time GW scheme (Rieger et al., Comp. Phys. Commun. 117, 211 (1999)) for the calculation of self-energies and related…

Condensed Matter · Physics 2009-10-31 L. Steinbeck , A. Rubio , L. Reining , M. Torrent , I. D. White , R. W. Godby

The Fast Multipole Method (FMM) obeys periodic boundary conditions "natively" if it uses a periodic Green function for computing the multipole expansion in the interaction zone of each FMM oct-tree node. One can define the "optimal" Green…

Computational Physics · Physics 2021-03-10 Nickolay Y. Gnedin

We investigate corrector estimates for the solutions of a thermoelasticity problem posed in a highly heterogeneous two-phase medium and its corresponding two-scale thermoelasticity model which was derived in an earlier paper by two-scale…

Analysis of PDEs · Mathematics 2017-02-13 Michael Eden , Adrian Muntean

The fundamental solution (Green function) for the Cauchy problem of the space-time fractional diffusion equation is investigated with respect to its scaling and similarity properties, starting from its Fourier-Laplace representation. Then,…

Probability · Mathematics 2007-10-02 Francesco Mainardi

A method based on separated integration to estimate anharmonic corrections to energy and vibration of molecules in a second-order diagrammatic vibrational many-body Green's function formalism has already been presented. A severe bottleneck…

Chemical Physics · Physics 2019-09-17 Prashant Rai , Khachik Sargsyan , Habib Najm , So Hirata

The Green's function coupled cluster (GFCC) method is a powerful many-body tool for computing the electronic structure of molecular and periodic systems, especially when electrons of the system are strongly correlated. However, for the GFCC…

Computational Physics · Physics 2019-04-18 Bo Peng , Roel Van Beeumen , David B. Williams-Young , Karol Kowalski , Chao Yang