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The current methods available to estimate gravitational shear from astronomical images of galaxies introduce systematic errors which can affect the accuracy of weak lensing cosmological constraints. We study the impact of KSB shape…

A large fraction of the information collected by cosmological surveys is simply discarded to avoid lengthscales which are difficult to model theoretically. We introduce a new technique which enables the extraction of useful information from…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-08 Fergus Simpson , J. Berian James , Alan F. Heavens , Catherine Heymans

The recent measurements of weak lensing by large-scale structure present significant new opportunities for studies of the matter distribution in the universe. Here, we present a new cosmic shear survey carried out with the Echelle…

Astrophysics · Physics 2009-11-07 David Bacon , Richard Massey , Alexandre Refregier , Richard Ellis

Residual errors in shear measurements, after corrections for instrument systematics and atmospheric effects, can impact cosmological parameters derived from weak lensing observations. Here we combine convergence maps from our suite of…

Cosmology and Nongalactic Astrophysics · Physics 2015-01-06 Andrea Petri , Morgan May , Zoltan Haiman , Jan M. Kratochvil

Weak gravitational lensing is responsible for the shearing and magnification of the images of high-redshift sources due to the presence of intervening matter. The distortions are due to fluctuations in the gravitational potential, and are…

Astrophysics · Physics 2009-09-29 D. Munshi , P. Valageas , L. Van Waerbeke , A. Heavens

Future large scale cosmological surveys will provide huge data sets whose analysis requires efficient data compression. Calculating accurate covariances is extremely challenging with increasing number of statistics used. Here we introduce a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Marika Asgari , Peter Schneider

We demonstrate and measure the impact of source galaxy clustering on higher-order summary statistics of weak gravitational lensing data. By comparing simulated data with galaxies that either trace or do not trace the underlying density…

With the advent of large-scale weak lensing surveys there is a need to understand how realistic, scale-dependent systematics bias cosmic shear and dark energy measurements, and how they can be removed. Here we describe how spatial…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-31 A. N. Taylor , T. D. Kitching

In this paper, we investigate the impact of higher-order distortions on the precise measurement of weak gravitational lensing shear and flexion. We begin by defining generalized higher-order distortions and outlining methods for measuring…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-01 Yuki Okura , Toshifumi Futamase

We study how joint shear and magnification measurements improve the statistical precision of weak lensing mass calibration experiments, relative to standard shear-only analysis. For our magnification measurements, we consider not only the…

Cosmology and Nongalactic Astrophysics · Physics 2010-09-30 Eduardo Rozo , Fabian Schmidt

Cosmic shear holds great promise for a precision independent measurement of $\Omega\rm_m$, the mass density of the universe relative to the critical density. The signal is expected to be weak, so a thorough understanding of systematic…

Astrophysics · Physics 2008-11-26 S. Asztalos , W. H. de Vries , L. J Rosenberg , T. Treadway , D. Burke , C. Claver , A. Saha , P. Puxley

Increasingly large areas in cosmic shear surveys lead to a reduction of statistical errors, necessitating to control systematic errors increasingly better. One of these systematic effects was initially studied by Hartlap et al. in 2011,…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-14 Eray Genc , Peter Schneider , Sandra Unruh , Tim Schrabback

As imaging surveys progress in exploring the large-scale structure of the Universe through the use of weak gravitational lensing, achieving subpercent accuracy in estimating shape distortions caused by lensing, or shear, is imperative for…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-22 Andy Park , Xiangchong Li , Rachel Mandelbaum

Only galaxies bright enough and large enough to be unambiguously identified and measured are included in galaxy surveys used to estimate cosmic shear. We demonstrate that because gravitational lensing can scatter galaxies across the…

Cosmology and Nongalactic Astrophysics · Physics 2009-08-17 Fabian Schmidt , Eduardo Rozo , Scott Dodelson , Lam Hui , Erin Sheldon

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

Studies of weak gravitational lensing by large-scale structures require the measurement of the distortions introduced to the shapes of distant galaxies at the few percent level by anisotropic light deflection along the line of sight. To…

Astrophysics · Physics 2009-11-07 Andrew W. Blain

In the theories with extra dimensions, gravitational waves can leak into extra dimensions, resulting in a reduction in the amplitude of the observed gravitational waves. Such an effect modifies the standard luminosity distance of…

General Relativity and Quantum Cosmology · Physics 2026-03-10 Xu-Jie Zhu , Ji-Yu Song , Tao Zhu , Xin Zhang

Cosmological analyses of second-order weak lensing statistics require precise and accurate covariance estimates. These covariances are impacted by two sometimes neglected terms: A negative contribution to the Gaussian covariance due to…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-04 Laila Linke , Pierre A. Burger , Sven Heydenreich , Lucas Porth , Peter Schneider

The aim of this paper is to discuss both higher-order asymptotic expansions and skewed approximations for the Bayesian Discrepancy Measure for testing precise statistical hypotheses. In particular, we derive results on third-order…

Methodology · Statistics 2025-05-02 Elena Bortolato , Francesco Bertolino , Monica Musio , Laura Ventura

In this paper we describe the predictions for the smoothed weak lensing shear and aperture-mass of two simple analytical models of the density field: the minimal tree-model and the stellar model. Both models give identical results for the…

Astrophysics · Physics 2009-11-10 Dipak Munshi , Patrick Valageas , Andrew J. Barber
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