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Related papers: Cosmic shear bispectrum from second-order perturba…

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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

Gravitational lensing distorts the cosmic microwave background (CMB) temperature and polarization fields and encodes valuable information on distances and growth rates at intermediate redshifts into the lensed power spectra. The…

Astrophysics · Physics 2008-11-26 Kendrick M. Smith , Wayne Hu , Manoj Kaplinghat

This paper details a description of the pattern of galaxy image distortion over the entire sky caused by the gravitational lensing which is the result of large scale inhomogeneities in our universe. We present a tensor spherical harmonic…

Astrophysics · Physics 2007-05-23 Albert Stebbins

When the gravitational lensing of the large-scale structure is calculated from a cosmological model a few assumptions enter: $(i)$ one assumes that the photons follow unperturbed background geodesics, which is usually referred to as the…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-28 Carolina Cuesta-Lazaro , Arnau Quera-Bofarull , Robert Reischke , Bjoern Malte Schaefer

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

Several conserved and/or gauge invariant quantities described as the second-order curvature perturbation have been given in the literature. We revisit various scenarios for the generation of second-order non-gaussianity in the primordial…

Astrophysics · Physics 2007-05-23 David H. Lyth , Yeinzon Rodriguez

Weak gravitational lensing observations probe the spectrum and evolution of density fluctuations and the cosmological parameters which govern them. At low redshifts, the non-linear gravitational evolution of large scale structure produces a…

Astrophysics · Physics 2009-10-31 Asantha Cooray , Wayne Hu

We propose a general formalism for galaxy biasing and apply it to methods for measuring cosmological parameters, such as regression of light versus mass, the analysis of redshift distortions, measures involving skewness and the cosmic…

Astrophysics · Physics 2009-10-30 Avishai Dekel , Ofer Lahav

We discuss the dominant terms of the relativistic galaxy number counts to second order in cosmological perturbation theory on sub-Hubble scales and on intermediate to large redshifts. In particular, we determine their contribution to the…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-13 Enea Di Dio , Ruth Durrer , Giovanni Marozzi , Francesco Montanari

General relativistic imprints on the galaxy bispectrum arise from observational (or projection) effects. The lightcone projection effects include local contributions from Doppler and gravitational potential terms, as well as lensing and…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-02 Sheean Jolicoeur , Obinna Umeh , Roy Maartens , Chris Clarkson

The greatest challenge in the interpretation of galaxy clustering data from any surveys is galaxy bias. Using a simple Fisher matrix analysis, we show that the bispectrum provides an excellent determination of linear and non-linear bias…

Astrophysics · Physics 2008-11-26 Emiliano Sefusatti , Eiichiro Komatsu

The population of compact extragalactic sources contribute to the non-Gaussianity at Cosmic Microwave Background frequencies. We study their non-Gaussianity using publicly available full-sky simulations. We introduce a parametrisation to…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-22 Fabien Lacasa

To render cosmic shear an astronomical tool of high precision, it is essential to eliminate systematic effects upon its signal, one of the most significant ones being correlations between the gravitational shear and the intrinsic…

Astrophysics · Physics 2008-10-21 B. Joachimi , P. Schneider

Squeezed primordial non-Gaussianity can strongly constrain early-universe physics, but it can only be observed on the CMB after it has been gravitationally lensed. We give a new simple non-perturbative prescription for accurately…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 Ruth Pearson , Antony Lewis , Donough Regan

Advances in upcoming weak lensing surveys pose new challenges for an accurate modeling of the lensing observables. The wide sky coverage of Euclid makes angular scales down to $l_\mathrm{min}=10$ accessible. At such large angular scales,…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-02 Nastassia Grimm , Jaiyul Yoo

In tomographic weak lensing surveys, the presence of nulling properties reveals symmetries inherent in the data, which rely solely on the geometrical properties of the Universe. Ensuring its validity thus provides us with constraints on the…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-05 David Touzeau , Francis Bernardeau , Karim Benabed , Sandrine Codis

Power spectra and cross-correlation measurements from the weak gravitational lensing of the cosmic microwave background (CMB) and the cosmic shearing of faint galaxies images will help shed light on quantities hidden from the CMB…

Astrophysics · Physics 2009-07-09 Wayne Hu

We present a Fisher information study of the statistical impact of galaxy bias and selection effects on the estimation of key cosmological parameters from galaxy redshift surveys; in particular, the angular diameter distance, Hubble…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-12 Nishant Agarwal , Vincent Desjacques , Donghui Jeong , Fabian Schmidt

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

We calculate the cosmic microwave background (CMB) bispectrum due to inhomogeneous reionization. We calculate all the terms that can contribute to the bispectrum that are products of first order terms on all scales in conformal Newtonian…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Rishi Khatri , Benjamin D. Wandelt