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We model weak gravitational lensing of light by large-scale structure using ray tracing through N-body simulations. The method is described with particular attention paid to numerical convergence. We investigate some of the key…

Astrophysics · Physics 2008-11-26 Chris Vale , Martin White

The paper introduces the weighted convolution, a novel approach to the convolution for signals defined on regular grids (e.g., 2D images) through the application of an optimal density function to scale the contribution of neighbouring…

Computer Vision and Pattern Recognition · Computer Science 2025-06-02 Simone Cammarasana , Giuseppe Patanè

I present a new algorithm, CALCLENS, for efficiently computing weak gravitational lensing shear signals from large N-body light cone simulations over a curved sky. This new algorithm properly accounts for the sky curvature and boundary…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-15 Matthew R. Becker

We present a 3D Bayesian method to model the kinematics of strongly lensed galaxies from spatially-resolved emission-line observations. This technique enables us to simultaneously recover the lens-mass distribution and the source kinematics…

Astrophysics of Galaxies · Physics 2018-09-21 Francesca Rizzo , Simona Vegetti , Filippo Fraternali , Enrico Di Teodoro

We present a combined cosmic shear analysis of the modeling of line-of-sight distortions on strongly lensed extended arcs and galaxy shape measurements in the COSMOS field. We develop a framework to predict the covariance of strong lensing…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-14 Felix Arjun Kuhn , Claudio Bruderer , Simon Birrer , Adam Amara , Alexandre Réfrégier

The proposed two-dimensional geometrically exact beam element extends our previous work by including the effects of shear distortion, and also of distributed forces and moments acting along the beam. The general flexibility-based…

Numerical Analysis · Mathematics 2025-08-06 Milan Jirasek , Martin Horak , Emma La Malfa Ribolla , Chiara Bonvissuto

Fourier ptychographic microscopy (FPM) is a novel computational coherent imaging technique for high space-bandwidth product imaging. Mathematically, Fourier ptychographic (FP) reconstruction can be implemented as a phase retrieval…

Computer Vision and Pattern Recognition · Computer Science 2016-07-19 Liheng Bian , Jinli Suo , Jaebum Chung , Xiaoze Ou , Changhuei Yang , Feng Chen , Qionghai Dai

We study the possibility of using quadrupole moments of auto-convolved galaxy images to measure cosmic shear. The autoconvolution of an image corresponds to the inverse Fourier transformation of its power spectrum. The new method has the…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-26 Xiangchong Li , Jun Zhang

(Abridged) We investigate and quantify the impact of finite simulation volume on weak lensing two- and four-point statistics. These {\it finite support} (FS) effects are modelled for several estimators, simulation box sizes and source…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Joachim Harnois-Deraps , Ludovic van Waerbeke

We report a detection of the coherent distortion of faint galaxies arising from gravitational lensing by foreground structures. This ``cosmic shear'' is potentially the most direct measure of the mass power spectrum, as it is unaffected by…

Astrophysics · Physics 2011-05-05 David Bacon , Alexandre Refregier , Richard Ellis

One of the primary limiting sources of systematic uncertainty in forthcoming weak lensing measurements is systematic uncertainty in the quantitative relationship between the distortions due to gravitational lensing and the measurable…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-10 Eric Huff , Rachel Mandelbaum

Weak gravitational lensing has become a common tool to constrain the cosmological model. The majority of the methods to derive constraints on cosmological parameters use second-order statistics of the cosmic shear. Despite their success,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Sandrine Pires , Adrienne Leonard , Jean-Luc Starck

Weak lensing by large-scale structure is a powerful technique to probe the dark components of the universe. To understand the measurement process of weak lensing and the associated systematic effects, image simulations are becoming…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-27 Claudio Bruderer , Chihway Chang , Alexandre Refregier , Adam Amara , Joel Berge , Lukas Gamper

The challenge in weak gravitational lensing caused by galaxies and clusters is to infer the projected mass density distribution from gravitational lensing measurements, known as the inversion problem. We introduce a novel theoretical…

Instrumentation and Methods for Astrophysics · Physics 2025-10-06 Jan Jakob , Björn Malte Schäfer

We compute statistical properties of weak gravitational lensing by large-scale structure in three Cold Dark Matter models. We use a P$^3$M $N$-body code to simulate the formation and evolution of large-scale structure in the universe. We…

Astrophysics · Physics 2009-10-31 Takashi Hamana , Hugo Martel , Toshifumi Futamase

Fourier light-field microscopy (FLFM) uses a micro-lens array (MLA) to segment the Fourier Plane of the microscopic objective lens to generate multiple two-dimensional perspective views, thereby reconstructing the three-dimensional(3D)…

Optics · Physics 2022-08-29 Haixin Huang , Haoyuan Qiu , Hanzhe Wu , Yihong Ji , Heng Li , Bin Yu , Danni Chen , Junle Qu

We develop a method for estimating the shear power spectra from weak lensing observations and test it on simulated data. Our method describes the shear field in terms of angular power spectra and cross correlation of the two shear modes…

Astrophysics · Physics 2008-11-26 Wayne Hu , Martin White

We develop an algorithm for the reconstruction of the two-dimensional mass distribution of a gravitational lens from the observable distortion of background galaxies. From the measured reduced shear, the lens mapping is obtained, from which…

Astrophysics · Physics 2009-10-31 Tarun Deep Saini , Somak Raychaudhury

Cosmic shear statistics, such as the two-point correlation function (2PCF), can be evaluated with the PDF-SYM method instead of the traditional weighted-sum approach. It makes use of the full PDF information of the shear estimators, and…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-18 Zhenjie Liu , Jun Zhang , Hekun Li , Zhi Shen , Cong Liu

We present MGLenS, a large series of modified gravity lensing simulations tailored for cosmic shear data analyses and forecasts in which cosmological and modified gravity parameters are varied simultaneously. Based on the FORGE and BRIDGE…