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Weak gravitational lensing has proven to be a powerful tool to map directly the distribution of dark matter in the Universe. The technique, currently used, relies on the accurate measurement of the gravitational shear that corresponds to…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 S. Pires , A. Amara

Luminosity profiles of galaxies acting as strong gravitational lenses can be tricky to study. Indeed, strong gravitational lensing images display several lensed components, both point-like and diffuse, around the lensing galaxy. Those…

Astrophysics of Galaxies · Physics 2015-12-23 J. Biernaux , P. Magain , D. Sluse , V. Chantry

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

Weak lensing provides a direct measure of the distribution of mass in the universe, and is therefore a uniquely powerful probe of dark matter. Weak lensing can also be used to measure the twin phenomenon of dark energy, via its effect upon…

Astrophysics · Physics 2007-05-23 Richard Massey , Alexandre Refregier , Jason Rhodes

Weak gravitational lensing seeks to determine shear by measuring induced quadrupole (elliptical) shapes in background galaxy images. Small impact parameter (a few kpc) gravitational lensing by foreground core masses between 2 10^{9} and 2…

Astrophysics · Physics 2014-10-13 John Irwin , Marina Shmakova

We present a comprehensive full-sky 3-dimensional analysis of the weak-lensing fields and their corresponding power spectra. Using the formalism of spin-weight spherical harmonics and spherical Bessel functions, we relate the two-point…

Astrophysics · Physics 2009-11-10 P. G. Castro , A. F. Heavens , T. D. Kitching

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

We revise and extend the stochastic approach to cumulative weak lensing (hereafter the sGL method) first introduced in Ref. [1]. Here we include a realistic halo mass function and density profiles to model the distribution of mass between…

Cosmology and Nongalactic Astrophysics · Physics 2011-01-19 Kimmo Kainulainen , Valerio Marra

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

Weak lensing by large-scale structure is a powerful probe of cosmology if the apparent alignments in the shapes of distant galaxies can be accurately measured. Most studies have therefore focused on improving the fidelity of the shape…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-24 Henk Hoekstra , Arun Kannawadi , Thomas D. Kitching

We revisit the performance and biases of the two-dimensional approach to galaxy-galaxy lensing. This method exploits the information for the actual positions and ellipticities of source galaxies, rather than using only the ensemble…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-03 Andrej Dvornik , Sebastiaan L. Zoutendijk , Henk Hoekstra , Konrad Kuijken

Given a foreground galaxy-density field or shear field, its cross-correlation with the shear field from a background population of source galaxies scales with the source redshift in a way that is specific to lensing. Such a source-scaling…

Astrophysics · Physics 2008-11-26 Jun Zhang , Lam Hui , Albert Stebbins

We investigate cosmological parameter inference from realistic simulated weak lensing image data using only galaxy position angles, as opposed to full-ellipticity information. We demonstrate that input shear fields can be accurately…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-30 Lee Whittaker

The available probes of the large scale structure in the Universe have distinct properties: galaxies are a high resolution but biased tracer of mass, while weak lensing avoids such biases but, due to low signal-to-noise ratio, has poor…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-28 Rafal M. Szepietowski , David J. Bacon , Joerg P. Dietrich , Michael Busha , Risa Wechsler , Peter Melchior

Weak gravitational lensing measurements based on photometry are limited by shape noise, the variance in the unknown unlensed orientations of the source galaxies. If the source is a disk galaxy with a well-ordered velocity field, however,…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-08 David Wittman , Matthew Self

Aims:Calibrating the point spread function (PSF) is a fundamental part of weak gravitational lensing analyses. Even with corrected galaxy images, imperfect calibrations can introduce biases. We propose an analytical framework for…

We present an end-to-end methodology to measure the effects of weak lensing on individual galaxy-galaxy systems exploiting their kinematic information. Using this methodology, we have measured a shear signal from the velocity fields of 18…

Astrophysics of Galaxies · Physics 2020-09-22 Pol Gurri , Edward N. Taylor , Christopher J. Fluke

Weak gravitational lensing has the potential to constrain cosmological parameters to high precision. However, as shown by the Shear TEsting Programmes (STEP) and GRavitational lEnsing Accuracy Testing (GREAT) Challenges, measuring galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Tomasz Kacprzak , Joe Zuntz , Barnaby Rowe , Sarah Bridle , Alexandre Refregier , Adam Amara , Lisa Voigt , Michael Hirsch

The measurement of cosmic shear using weak gravitational lensing is a challenging task that involves a number of complicated procedures. We study in detail the systematic errors in the measurement of weak lensing Minkowski Functionals…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Masato Shirasaki , Naoki Yoshida

The arrival times, positions, and fluxes of multiple images in strong lens systems can be used to infer the presence of dark subhalos in the deflector, and thus test predictions of cold dark matter models. However, gravitational lensing…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-16 Daniel Gilman , Adriano Agnello , Tommaso Treu , Charles R. Keeton , Anna M. Nierenberg
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