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Related papers: Fast Multipole Method for Gravitational Lensing. A…

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We present a fast algorithm to produce light curves of distant stars undergoing microlensing near critical curves. The need of these type of algorithms is motivated by recent observations of microlensing events of distant stars at high…

Instrumentation and Methods for Astrophysics · Physics 2022-10-05 J. M. Diego

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

The Fast Multipole Method (FMM) reduces the computation of pairwise two-body interactions among $N$-particles to order $N$, whose computation cost should be of order $N^2$ by brute force. However, its implementation is somewhat complicated…

Computational Physics · Physics 2020-09-03 Yasuhiro Kajima

High redshift sources suffer from magnification or demagnification due to weak gravitational lensing by large scale structure. One consequence of this is that the distance-redshift relation, in wide use for cosmological tests, suffers…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Madhura Killedar , Paul D. Lasky , Geraint F. Lewis , Chris J. Fluke

We propose fast, exact and efficient algorithms for the convolution of two arbitrary functions on the sphere which speed up computations by a factor \order{\sqrt{N}} compared to present methods where $N$ is the number of pixels. No…

Astrophysics · Physics 2009-10-31 Benjamin D. Wandelt , Krzysztof M. Gorski

Motivated by the limitations encountered with the commonly used direct reconstruction techniques of producing mass maps, we have developed a multi-resolution maximum-likelihood reconstruction method for producing two dimensional mass maps…

Astrophysics · Physics 2009-11-13 H. Khiabanian , I. P. Dell'Antonio

Recent studies have demonstrated improved skill in numerical weather prediction via the use of spatially correlated observation error covariance information in data assimilation systems. In this case, the observation weighting matrices…

Numerical Analysis · Mathematics 2022-01-05 Guannan Hu , Sarah L. Dance

In this brief communication a new method is outlined for modelling magnification patterns on an observer's plane using a first order approximation to the null geodesic path equations for a point mass lens. For each ray emitted from a…

Instrumentation and Methods for Astrophysics · Physics 2017-02-08 S. J. Walters , L. K. Forbes

We present an extension to multiple planes of the gravitational lensing code {\small GLAMER}. The method entails projecting the mass in the observed light-cone onto a discrete number of lens planes and inverse ray-shooting from the image to…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Margarita Petkova , R. Benton Metcalf , Carlo Giocoli

A fast multipole method (FMM) for asymptotically smooth kernel functions (1/r, 1/r^4, Gauss and Stokes kernels, radial basis functions, etc.) based on a Chebyshev interpolation scheme has been introduced in [Fong et al., 2009]. The method…

Numerical Analysis · Computer Science 2012-11-21 Matthias Messner , Bérenger Bramas , Olivier Coulaud , Eric Darve

In this work we present a variant of the fast multipole method (FMM) for efficiently evaluating standard layer potentials on geometries with complex coordinates in two and three dimensions. The complex scaled boundary integral method for…

Numerical Analysis · Mathematics 2025-10-20 Tristan Goodwill , Leslie Greengard , Jeremy Hoskins , Manas Rachh , Yuguan Wang

We investigate interferometric techniques to estimate the deflection angle of an optical beam and compare them to the direct detection of the beam deflection. We show that quantum metrology methods lead to a unifying treatment for both…

Quantum Physics · Physics 2020-08-12 S. P. Walborn , G. H. Aguilar , P. L. Saldanha , L. Davidovich , R. L. de Matos Filho

A robust stellar initial mass function (IMF) is crucial in any studies related to star formation. However, the direct measurement of the stellar IMF is confined to the local universe, limited by the resolving power of telescopes. Recently,…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-12 Sung Kei Li

Rotation measure (RM) synthesis is a widely used polarization processing algorithm for reconstructing polarized structures along the line of sight. Performing RM synthesis on large datasets produced by telescopes like LOFAR can be…

Instrumentation and Methods for Astrophysics · Physics 2018-10-16 S. S. Sridhar , G. Heald , J. M. van der Hulst

Robust estimation is essential in computer vision, robotics, and navigation, aiming to minimize the impact of outlier measurements for improved accuracy. We present a fast algorithm for Geman-McClure robust estimation, FracGM, leveraging…

Computer Vision and Pattern Recognition · Computer Science 2024-11-22 Bang-Shien Chen , Yu-Kai Lin , Jian-Yu Chen , Chih-Wei Huang , Jann-Long Chern , Ching-Cherng Sun

We present an algorithm to parallelize the inverse fast multipole method (IFMM), which is an approximate direct solver for dense linear systems. The parallel scheme is based on a greedy coloring algorithm, where two nodes in the hierarchy…

Computational Physics · Physics 2020-02-19 Toru Takahashi , Chao Chen , Eric Darve

We present a new gravitational lens modelling technique designed to model high-resolution interferometric observations with large numbers of visibilities without the need to pre-average the data in time or frequency. We demonstrate the…

Instrumentation and Methods for Astrophysics · Physics 2021-01-06 Devon Powell , Simona Vegetti , John P. McKean , Cristiana Spingola , Francesca Rizzo , Hannah R. Stacey

Fluorescence lifetime imaging microscopy (FLIM) is a powerful technique in biomedical research that uses the fluorophore decay rate to provide additional contrast in fluorescence microscopy. However, at present, the calculation, analysis,…

Image and Video Processing · Electrical Eng. & Systems 2021-06-09 Varun Mannam , Yide Zhang , Xiaotong Yuan , Cara Ravasio , Scott S. Howard

We present a new algorithm, FRiM (FRactal Iterative Method), aiming at the reconstruction of the optical wavefront from measurements provided by a wavefront sensor. As our application is adaptive optics on extremely large telescopes, our…

Mathematical Physics · Physics 2015-05-18 Eric Thiebaut , Michel Tallon

This article presents a fast direct solver, termed Algebraic Inverse Fast Multipole Method (from now on abbreviated as AIFMM), for linear systems arising out of $N$-body problems. AIFMM relies on the following three main ideas: (i) Certain…

Numerical Analysis · Mathematics 2023-01-31 Vaishnavi Gujjula , Sivaram Ambikasaran