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

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In this paper, a fast multipole method (FMM) is proposed to compute long-range interactions of wave sources embedded in 3-D layered media. The layered media Green's function for the Helmholtz equation, which satisfies the transmission…

Numerical Analysis · Mathematics 2020-01-08 Bo Wang , Wenzhong Zhang , Wei Cai

Large matrix multiplication is a cornerstone of modern machine learning workloads, yet traditional approaches suffer from cubic computational complexity (e.g., $\mathcal{O}(n^3)$ for a matrix of size $n\times n$). We present Low-Rank GEMM,…

Performance · Computer Science 2025-11-25 Alfredo Metere

The line-of-sight structure of the Galactic magnetic field (GMF) can be studied using Faraday rotation measure (RM) grids. We analyze how the choice of interpolation kernel can affect the accuracy and reliability of reconstructed RM maps.…

Instrumentation and Methods for Astrophysics · Physics 2024-12-24 Affan Khadir , Ayush Pandhi , Sebastian Hutschenreuter , Bryan Gaensler , Shannon Vanderwoude , Jennifer West , Shane O'Sullivan

Removing optical and atmospheric blur from galaxy images significantly improves galaxy shape measurements for weak gravitational lensing and galaxy evolution studies. This ill-posed linear inverse problem is usually solved with…

Instrumentation and Methods for Astrophysics · Physics 2023-03-29 Tianao Li , Emma Alexander

This paper is concerned with the modeling errors appeared in the numerical methods of inverse medium scattering problems (IMSP). Optimization based iterative methods are wildly employed to solve IMSP, which are computationally intensive due…

Numerical Analysis · Mathematics 2021-02-23 Junxiong Jia , Bangyu Wu , Jigen Peng , Jinghuai Gao

We propose a new, two-stage algorithm for inverting strong gravitational lenses. The key to the algorithm is decoupling the effects of lens magnification and intrinsic structure in the background source in the appearance of lensed arcs.…

Astrophysics · Physics 2007-05-23 P. Newbury , G. G. Fahlman

The gravitational field of compact objects, such as primordial black holes, can create multiple images of background sources. For transients such as fast radio bursts (FRBs), these multiple images can be resolved in the time domain. Under…

We present the observational results of a survey for strong gravitational lens systems consisting of extended emission-line galaxies lensed by intervening early-type galaxies, conducted using integral field units (IFUs) of the Magellan…

Astrophysics · Physics 2008-11-26 Adam S. Bolton , Scott Burles

Learning a Gaussian Mixture Model (GMM) is hard when the number of parameters is too large given the amount of available data. As a remedy, we propose restricting the GMM to a Gaussian Markov Random Field Mixture Model (GMRF-MM), as well as…

Machine Learning · Computer Science 2022-01-25 Shahaf E. Finder , Eran Treister , Oren Freifeld

As research into magnetic thin films and spintronics devices is moving from single to multiple magnetic layers, there is a need for micromagnetics modelling tools specifically designed to efficiently handle magnetic multilayers. Here we…

Mesoscale and Nanoscale Physics · Physics 2019-07-19 Serban Lepadatu

We describe a new method for measuring galaxy magnification due to weak gravitational lensing. Our method makes use of a tight scaling relation between galaxy properties that are modified by gravitational lensing, such as apparent size, and…

Cosmology and Nongalactic Astrophysics · Physics 2011-11-07 Eric M. Huff , Genevieve J. Graves

We demonstrate a new computational illumination technique that achieves large space-bandwidth-time product, for quantitative phase imaging of unstained live samples in vitro. Microscope lenses can have either large field of view (FOV) or…

Optics · Physics 2015-10-16 Lei Tian , Ziji Liu , Li-Hao Yeh , Michael Chen , Jingshan Zhong , Laura Waller

The kernel-independent fast multipole method (KIFMM) proposed in [1] is of almost linear complexity. In the original KIFMM the time-consuming M2L translations are accelerated by FFT. However, when more equivalent points are used to achieve…

Numerical Analysis · Computer Science 2015-03-19 Yanchuang Cao , Lihua Wen , Junjie Rong

We present an analytical formulation of gravitational lensing using familiar triaxial power-law mass distributions, where the 3-dimensional mass density is given by $\rho(X,Y,Z) = \rho_0 [1 + (\frac{X}{a})^2 + (\frac{Y}{b})^2 +…

Astrophysics · Physics 2009-10-30 Kyu-Hyun Chae , Valery K. Khersonsky , David A. Turnshek

Non-uniform fast Fourier Transform (NUFFT) and inverse NUFFT (INUFFT) algorithms, based on the Fast Multipole Method (FMM) are developed and tested. Our algorithms are based on a novel factorization of the FFT kernel, and are implemented…

Numerical Analysis · Computer Science 2016-11-30 Nail A. Gumerov , Ramani Duraiswami

In this work we introduced a new proposal to study the gravitational lensing theory by spherical lenses, starting from its surface mass density $\Sigma(x)$ written in terms of a decreasing function $f$ of a dimensionless coordinate $x$ on…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-21 Roger Hurtado , Leonardo Castaneda , Juan M. Tejeiro

In this paper, we present a numerical algorithm for the accurate and efficient computation of the convolution of the frequency domain layered media Green's function with a given density function. Instead of compressing the convolution…

Numerical Analysis · Mathematics 2020-06-16 Min Hyung Cho , Jingfang Huang

Given an observed gravitational lens mirage produced by a foreground deflector (cf. galaxy, quasar, cluster,...), it is possible via numerical lens inversion to retrieve the real source image, taking full advantage of the magnifying power…

Instrumentation and Methods for Astrophysics · Physics 2010-06-08 J. Surdej , C. Delacroix , P. Coleman , M. Dominik , S. Habraken , C. Hanot , H. Le Coroller , D. Mawet , H. Quintana , T. Sadibekova , D. Sluse

Composite function minimization captures a wide spectrum of applications in both computer vision and machine learning. It includes bound constrained optimization and cardinality regularized optimization as special cases. This paper proposes…

Optimization and Control · Mathematics 2016-12-08 Ganzhao Yuan , Wei-Shi Zheng , Bernard Ghanem

A common problem in cosmology is to integrate the product of two or more spherical Bessel functions (sBFs) with different configuration-space arguments against the power spectrum or its square, weighted by powers of wavenumber. Naively…

Cosmology and Nongalactic Astrophysics · Physics 2019-12-03 Zachary Slepian , Yin Li , Marcel Schmittfull , Zvonimir Vlah