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Related papers: A Novel Framework for Modeling Weakly Lensing Shea…

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A long standing problem in weak lensing is about how to construct cosmic shear estimators from galaxy images. Conventional methods average over a single quantity per galaxy to estimate each shear component. We show that any such shear…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Jun Zhang , Eiichiro Komatsu

The principles of measuring the shapes of galaxies by a model-fitting approach are discussed in the context of shape-measurement for surveys of weak gravitational lensing. It is argued that such an approach should be optimal, allowing…

Astrophysics · Physics 2009-11-13 L. Miller , T. D. Kitching , C. Heymans , A. F. Heavens , L. Van Waerbeke

We present a novel framework for jointly modelling the weak lensing source galaxy redshift distribution and the intrinsic alignment of galaxies via a shared luminosity function (LF). Considering this framework within the context of a Rubin…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-13 Nikolina Šarčević , C. Danielle Leonard , Markus M. Rau , LSST Dark Energy Science Collaboration

In this paper, we develop a new gravitational lensing inversion technique. While traditional approaches assume that the lensing field varies little across a galaxy image, we note that this variation in the field can give rise to a…

Astrophysics · Physics 2009-11-10 David M. Goldberg , David J. Bacon

The high sensitivity of the new generation of radio telescopes such as the Square Kilometre Array (SKA) will allow cosmological weak lensing measurements at radio wavelengths that are competitive with optical surveys. We present an…

Instrumentation and Methods for Astrophysics · Physics 2016-09-23 Marzia Rivi , Lance Miller , Sphesihle Makhathini , Filipe Batoni Abdalla

We study the bias and scatter in mass measurements of galaxy clusters resulting from fitting a spherically-symmetric Navarro, Frenk & White model to the reduced tangential shear profile measured in weak lensing observations. The reduced…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-23 Matthew R. Becker , Andrey V. Kravtsov

Weak lensing surveys exploit measurements of galaxy ellipticities. These measurements are subject to errors which degrade the cosmological information that can be extracted from the surveys. Here we propose a way of using the galaxy data…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-07 Alberto Vallinotto , Scott Dodelson , Pengjie Zhang

The current weak lensing measurements of the large scale structure are mostly related to statistical study of background galaxy ellipticities. We consider a possibility to extend lensing studies with intrinsically unresolved sources and…

Astrophysics · Physics 2008-11-26 Asantha Cooray

The Shear TEsting Programme, STEP, is a collaborative project to improve the accuracy and reliability of all weak lensing measurements in preparation for the next generation of wide-field surveys. In this first STEP paper we present the…

Weak lensing by large scale structure or 'cosmic shear' is a potentially powerful cosmological probe to shed new light on Dark Matter, Dark Energy and Modified Gravity. It is based on the weak distortions induced by large-scale structures…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-11 Alexandre Refregier , Adam Amara

We investigate biases induced by the conversion between the observed image shape to shear distortion in current weak lensing analysis methods. Such overall calibration biases cannot be detected by the standard tests such as E/B…

Astrophysics · Physics 2009-11-07 Christopher M. Hirata , Uros Seljak

The analysis of strong lensing images usually involves an external convergence and shear, which are meant to model the effect of perturbations along the line of sight, on top of the main lens. Such a description of line-of-sight…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-04 Théo Duboscq , Natalie B. Hogg , Pierre Fleury , Julien Larena

We present weak lensing shear catalogues from the fourth data release of the Kilo-Degree Survey, KiDS-1000, spanning 1006 square degrees of deep and high-resolution imaging. Our `gold-sample' of galaxies, with well-calibrated photometric…

We explore the dependence of weak lensing phenomena on the background cosmology. We first generalise the relation between $P_\psi(\omega)$, the angular power spectrum of the distortion, and the power spectrum of density fluctuations to…

Astrophysics · Physics 2009-10-28 Nick Kaiser

Most of the matter in the universe is not luminous and can be observed directly only through its gravitational effect. An emerging technique called weak gravitational lensing uses background galaxies to reveal the foreground dark matter…

Weak gravitational lensing is a unique probe of the dark side of the universe: it provides a direct way to map the distribution of dark matter around galaxies, clusters of galaxies and on cosmological scales. Furthermore, the measurement of…

Astrophysics · Physics 2010-01-07 Henk Hoekstra , Bhuvnesh Jain

We investigate the effects of weak gravitational lensing in the standard Cold Dark Matter cosmology, using an algorithm which evaluates the shear in three dimensions. The algorithm has the advantage of variable softening for the particles,…

Astrophysics · Physics 2009-10-31 Andrew J. Barber , Peter A. Thomas , H. M. P. Couchman

The standard theory of weak gravitational lensing relies on the infinitesimal light beam approximation. In this context, images are distorted by convergence and shear, the respective sources of which unphysically depend on the resolution of…

General Relativity and Quantum Cosmology · Physics 2017-11-08 Pierre Fleury , Julien Larena , Jean-Philippe Uzan

In order to reach the required performance of Stage-III and IV weak lensing surveys, cosmic shear measurements have to rely on external simulations to calibrate residual biases. Over the years, several techniques have been developed to…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-11 G. Congedo , A. N. Taylor

We use a new non-parametric gravitational modelling tool -- \Glass{} -- to determine what quality of data (strong lensing, stellar kinematics, and/or stellar masses) are required to measure the circularly averaged mass profile of a lens and…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Jonathan P. Coles , Justin I. Read , Prasenjit Saha