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Related papers: COSEBIs: Extracting the full E-/B-mode information…

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We compute the angular power spectrum of the $B$-modes of the weak-lensing shear in a spatially anisotropic spacetime. We find that there must also exist off-diagonal correlations between the $E$-modes, $B$-modes, and convergence that allow…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-13 Thiago S. Pereira , Cyril Pitrou , Jean-Philippe Uzan

Weak gravitational lensing is a widely used probe in cosmological analysis. It allows astrophysists to understand the content and evolution of the Universe. We are entering an era where we are not limited by the data volume but by…

Instrumentation and Methods for Astrophysics · Physics 2026-03-20 Axel Guinot , Rachel Mandelbaum

We develop a Bayesian hierarchical modelling approach for cosmic shear power spectrum inference, jointly sampling from the posterior distribution of the cosmic shear field and its (tomographic) power spectra. Inference of the shear power…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-11 Justin Alsing , Alan Heavens , Andrew H. Jaffe , Alina Kiessling , Benjamin Wandelt , Till Hoffmann

We calculate the CMB anisotropy in compact hyperbolic universe models using the regularized method of images described in paper-I, including the 'line-of-sight `integrated Sachs-Wolfe' effect, as well as the last-scattering surface terms.…

Astrophysics · Physics 2009-10-31 J. Richard Bond , Dmitry Pogosyan , Tarun Souradeep

We discuss the synergy of the cosmic shear and CMB lensing experiments to simultaneously constrain the neutrino mass and dark energy properties. Taking fully account of the CMB lensing, cosmic shear, CMB anisotropies, and their cross…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-21 Toshiya Namikawa , Shun Saito , Atsushi Taruya

We present a Bayesian hierarchical modelling approach to infer the cosmic matter density field, and the lensing and the matter power spectra, from cosmic shear data. This method uses a physical model of cosmic structure formation to infer…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-03 Natalia Porqueres , Alan Heavens , Daniel Mortlock , Guilhem Lavaux

The detection of B-modes in the CMB polarization pattern is a major issue in modern cosmology and must therefore be handled with analytical methods that produce reliable results. We describe a method that uses the frequency dependency of…

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

Cosmic shear measurements rely on our ability to measure and correct the Point Spread Function (PSF) of the observations. This PSF is measured using stars in the field, which give a noisy measure at random points in the field. Using Wiener…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 A. Amara , A. Refregier , S. Paulin-Henriksson

Stripe 82 in the Sloan Digital Sky Survey was observed multiple times, allowing deeper images to be constructed by coadding the data. Here we analyze the ellipticities of background galaxies in this 275 square degree region, searching for…

Since cosmic shear was first observed in 2000, it has become a key cosmological probe and promises to deliver exquisite dark energy constraints. However, shear is inferred from coherent distortions of galaxy shapes, and the relation between…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-19 Enya Van den Abeele , Pierre Astier , Anna Niemiec

We present simulations of a cosmic shear survey and show how the survey geometry influences the accuracy of determination of cosmological parameters. We numerically calculate the full covariance matrices of the two-point statistics \xi_+,…

Astrophysics · Physics 2007-05-23 Martin Kilbinger

The correlation between cosmic shear as measured by the image distortion of high-redshift galaxies and the number counts of foreground galaxies is calculated. For a given power spectrum of the cosmic density fluctuations, this correlation…

Astrophysics · Physics 2009-10-30 Peter Schneider

We derive constraints on a coupled quintessence model with pure momentum exchange from the public $\sim$1000 deg$^2$ cosmic shear measurements from the Kilo-Degree Survey and the $\it{Planck}$ 2018 Cosmic Microwave Background data. We…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-16 A. Spurio Mancini , A. Pourtsidou

As an alternative explanation of the dimming of distant supernovae it has recently been advocated that we live in a special place in the Universe near the centre of a large spherical void described by a Lemaitre-Tolman-Bondi (LTB) metric.…

Astrophysics · Physics 2009-10-02 Juan Garcia-Bellido , Troels Haugboelle

We propose to use a simple observable, the fractional area of "hot spots" in weak lensing mass maps which are detected with high significance, to determine background cosmological parameters. Because these high-shear regions are directly…

Astrophysics · Physics 2008-09-24 Sheng Wang , Zoltan Haiman , Morgan May , John Kehayias

We develop a new method of extracting simultaneous measurements of weak lensing shear and a local rotation of the plane of polarization using observations of resolved radio sources. We show that the direction of polarization is…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-28 Lee Whittaker , Richard A. Battye , Michael L. Brown

We present a three dimensional cosmic shear analysis of the Hubble Space Telescope COSMOS survey, the largest ever optical imaging program performed in space. We have measured the shapes of galaxies for the tell-tale distortions caused by…

The integrated shear 3-point correlation function $\zeta_{\pm}$ is a higher-order statistic of the cosmic shear field that describes the modulation of the 2-point correlation function $\xi_{\pm}$ by long-wavelength features in the field.…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-16 Anik Halder , Alexandre Barreira

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