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Related papers: The spherical Fast Multipole Method (sFMM) for Gra…

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Visual SLAM is particularly challenging in environments affected by noise, varying lighting conditions, and darkness. Learning-based optical flow algorithms can leverage multiple modalities to address these challenges, but traditional…

Computer Vision and Pattern Recognition · Computer Science 2025-06-25 Youjie Zhou , Guofeng Mei , Yiming Wang , Yi Wan , Fabio Poiesi

The structure of force-free, steady and axisymmetric magnetosphere of a neutron star (NS) is governed by the Grad-Shafranov (GS) equation, which is a second-order differential equation but degrades to first-order on the light surface (LS).…

High Energy Astrophysical Phenomena · Physics 2018-07-18 Lei Huang , Zhen Pan , Cong Yu

We present the experimental implementation of simultaneous spatial multimode demultiplexing as a distance measurement tool. We first show a simple and intuitive derivation of the Fisher information in the presence of Poissonian noise. We…

Optics · Physics 2020-08-06 Pauline Boucher , Claude Fabre , Guillaume Labroille , Nicolas Treps

Gravitational lensing directly measures mass density fluctuations along the lines of sight to very distant objects. No assumptions need to be made concerning bias, the ratio of fluctuations in galaxy density to mass density. Hence, lensing…

Astrophysics · Physics 2007-05-23 Joachim Wambsganss , Renyue Cen , Jeremiah P. Ostriker

While fast multipole methods (FMMs) are in widespread use for the rapid evaluation of potential fields governed by the Laplace, Helmholtz, Maxwell or Stokes equations, their coupling to high-order quadratures for evaluating layer potentials…

Numerical Analysis · Mathematics 2021-04-26 Leslie Greengard , Michael O'Neil , Manas Rachh , Felipe Vico

Online augmentation of an oblique aerial image sequence with structural information is an essential aspect in the process of 3D scene interpretation and analysis. One key aspect in this is the efficient dense image matching and depth…

Computer Vision and Pattern Recognition · Computer Science 2019-09-24 Boitumelo Ruf , Thomas Pollok , Martin Weinmann

We describe a version of an algorithm for evolving self-gravitating collections of particles that should be nearly ideal for parallel architectures. Our method is derived from the ``self-consistent field'' (SCF) approach suggested…

Astrophysics · Physics 2016-08-30 Lars Hernquist , Steinn Sigurdsson , Greg L. Bryan

Gravitational lensing is the deflection of light rays due to the gravity of intervening masses. This phenomenon is observed in a variety of scales and configurations, involving any non-uniform mass such as planets, stars, galaxies, clusters…

We develop a model of gravitational lensing in a non-uniform plasma. When a gravitating body is surrounded by a plasma, the lensing angle depends on the frequency of the electromagnetic wave, due to dispersion properties of plasma, in…

Cosmology and Nongalactic Astrophysics · Physics 2010-06-14 G. S. Bisnovatyi-Kogan , O. Yu. Tsupko

We propose a simple and computationally fast method for performing N-body simulations for a large class of modified gravity theories with a screening mechanism such as chameleons, symmetrons and galileons. By combining the linear…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Hans A. Winther , Pedro G. Ferreira

Gravitational lensing is a crucial tool for exploring cosmic phenomena, providing insights into galaxy clustering, dark matter, and dark energy. Given the substantial computational demands of $N$-body simulations, approximate methods like…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-31 Viviane Alfradique , Tiago Castro , Valerio Marra , Miguel Quartin , Carlo Giocoli , Pierluigi Monaco

Deep cosmic microwave background polarization experiments allow a very precise internal reconstruction of the gravitational lensing signal in pricinple. For this aim, likelihood-based or Bayesian methods are typically necessary, where very…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-25 Martin Reinecke , Sebastian Belkner , Julien Carron

Fast Multipole Methods (FMMs) based on the oscillatory Helmholtz kernel can reduce the cost of solving N-body problems arising from Boundary Integral Equations (BIEs) in acoustic or electromagnetics. However, their cost strongly increases…

Numerical Analysis · Mathematics 2022-02-11 Igor Chollet , Xavier Claeys , Pierre Fortin , Laura Grigori

The efficient simulation of isotropic Gaussian random fields on the unit sphere is a task encountered frequently in numerical applications. A fast algorithm based on Markov properties and fast Fourier Transforms in 1d is presented that…

Numerical Analysis · Mathematics 2018-04-16 Peter E. Creasey , Annika Lang

The Fast Multipole Method (FMM) computes pairwise interactions between particles with an efficiency that scales linearly with the number of particles. The method works by grouping particles based on their spatial distribution and…

Computational Physics · Physics 2025-08-05 He Zhang

We present GridFF, an efficient method for simulating molecules on rigid substrates, derived from techniques used in protein-ligand docking in biochemistry. By projecting molecule-substrate interactions onto precomputed spatial grids with…

Chemical Physics · Physics 2025-08-22 Indranil Mal , Milan Kočí , Paolo Nicolini , Prokop Hapala

This paper presents a new boundary integral equation (BIE) method for simulating particulate and multiphase flows through periodic channels of arbitrary smooth shape in two dimensions. The authors consider a particular system---multiple…

Numerical Analysis · Mathematics 2015-10-20 Gary Marple , Alex Barnett , Adrianna Gillman , Shravan Veerapaneni

We develop a sampling scheme on the sphere that permits accurate computation of the spherical harmonic transform and its inverse for signals band-limited at $L$ using only $L^2$ samples. We obtain the optimal number of samples given by the…

Information Theory · Computer Science 2014-07-25 Zubair Khalid , Rodney A. Kennedy , Jason D. McEwen

Statistical analyses of observed galaxy distortions are often used to reconstruct the mass distribution of an intervening cluster responsible for gravitational lensing. In current projects, distortions of thousands of source galaxies have…

Astrophysics · Physics 2007-05-23 Marco Lombardi , Giuseppe Bertin

To use strong gravitational lenses as an astrophysical or cosmological probe, models of their mass distributions are often needed. We present a new, time-efficient automation code for uniform modeling of strongly lensed quasars with GLEE, a…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-29 S. Ertl , S. Schuldt , S. H. Suyu , T. Schmidt , T. Treu , S. Birrer , A. J. Shajib , D. Sluse