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We present new results on the gravitational lensing shear and magnification power spectra obtained from numerical simulations of a flat cosmology with a cosmological constant. These results are of considerable interest since both the shear…

Astrophysics · Physics 2009-11-07 Andrew J. Barber , A. N. Taylor

Clustering of the large scale structure provides complementary information to the measurements of the cosmic microwave background anisotropies through power spectrum and bispectrum of density perturbations. Extracting the bispectrum…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-19 Ji-Ping Dai , Licia Verde , Jun-Qing Xia

The standard weak lensing formalism assumes that the lensing map relating the observed image of a source to its intrinsic shape depends only on the deflection angle. We show that this description is incomplete beyond linear perturbation…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-26 Matteo Magi , Francesca Lepori , Julian Adamek

Galaxy surveys contain information on the largest scales via wide-angle and relativistic contributions. By combining two different galaxy populations, we can suppress the strong cosmic variance on ultra-large scales and thus enhance the…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-26 Sheean Jolicoeur , Sêcloka L. Guedezounme , Roy Maartens , Pritha Paul , Chris Clarkson , Stefano Camera

Lensing of the CMB by modes that are larger than the size of the survey dilates intrinsic scales in the temperature and polarization fields and coherently shifts their observed power spectra with respect to the ensemble or all-sky mean. The…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-09 Alessandro Manzotti , Wayne Hu , Aurélien Benoit-Lévy

Observed CMB anisotropies are lensed, and the lensed power spectra can be calculated accurately assuming the lensing deflections are Gaussian. However, the lensing deflections are actually slightly non-Gaussian due to both non-linear…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-12 Antony Lewis , Geraint Pratten

Weak lensing by large scale structure induces correlated ellipticities in the images of distant galaxies. The two-point correlation is determined by the matter power spectrum along the line of sight. We use the fully nonlinear evolution of…

Astrophysics · Physics 2009-10-28 Bhuvnesh Jain , Uros Seljak

Coherent properties of the baryon-photon fluid decoupling are considered in the terms of an effective nonlinear Schr\"{o}dinger equation for a macroscopic wave function that specifies the index of the coherent state. Generation of a…

Astrophysics · Physics 2008-04-07 A. Bershadskii

We produce mock angular catalogues from simulations with different initial power spectra to test methods that recover measures of clustering in three dimensions, such as the power spectrum, variance and higher order cumulants. We find that…

Astrophysics · Physics 2020-11-25 E. Gaztanaga , C. M. Baugh

A method of general applicability has been developed, whereby the null geodesic equations of the Einstein-Straus-de Sitter metric can be integrated simultaneously in terms of the curvature constant $k$. The purpose is to generalize the…

General Relativity and Quantum Cosmology · Physics 2024-09-06 Mourad Guenouche

Future lensing surveys will be nearly full-sky and reach an unprecedented depth, probing scales closer and closer to the Hubble radius. This motivates the study of the cosmic shear beyond the small-angle approximation and including general…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-09 Francis Bernardeau , Camille Bonvin , Nicolas Van de Rijt , Filippo Vernizzi

Analyses of cosmic shear typically condense weak lensing information over a range of scales to a single cosmological parameter, $S_8$. This paper presents a method to extract more information from Stage-IV cosmic shear measurements by…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-30 Calvin Preston , Alexandra Amon , George Efstathiou

The effect of our Galaxy's motion through the Cosmic Microwave Background rest frame, which aberrates and Doppler shifts incoming photons measured by current CMB experiments, has been shown to produce mode-mixing in the multipole space…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-14 Amanda Yoho , Craig J. Copi , Glenn D. Starkman , Thiago S. Pereira

Selected results on estimating cosmological parameters from simulated weak lensing data with noise are presented. Numerical simulations of ray tracing through N-body simulations have been used to generate shear and convergence maps due to…

Astrophysics · Physics 2007-05-23 Bhuvnesh Jain , Uros Seljak , Simon White

We present a method for suppressing contributions from higher-order terms in perturbation theory, greatly increasing the amount of information which may be extracted from the matter power spectrum. In an evolved cosmological density field…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-30 Fergus Simpson , Alan F. Heavens , Catherine Heymans

We calculate corrections to the power spectrum predictions of weak lensing by large scale structure due to higher order effects in the gravitational potential. Using a perturbative approach to third order in transverse displacements, we…

Astrophysics · Physics 2011-05-12 Asantha Cooray , Wayne Hu

Upcoming galaxy surveys will allow us to probe the growth of the cosmic large-scale structure with improved sensitivity compared to current missions, and will also map larger areas of the sky. This means that in addition to the increased…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-31 Matteo Martinelli , Roohi Dalal , Fereshteh Majidi , Yashar Akrami , Stefano Camera , Elena Sellentin

In this paper, we study how to directly measure the effect of peculiar velocities in the observed angular power spectra. We do this by constructing a new anti-symmetric estimator of Large Scale Structure using different dark matter tracers.…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-03 José Fonseca , Chris Clarkson

We introduce a diluted version of the one dimensional spin-glass model with interactions decaying in probability as an inverse power of the distance. In this model varying the power corresponds to change the dimension in short-range models.…

Disordered Systems and Neural Networks · Physics 2009-11-13 L. Leuzzi , G. Parisi , F. Ricci-Tersenghi , J. J. Ruiz-Lorenzo

Dark matter and dark energy are usually assumed to couple only gravitationally. An extension to this picture is to model dark energy as a scalar field coupled directly to cold dark matter. This coupling leads to new physical effects, such…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Francesco Pace , Marco Baldi , Lauro Moscardini , David Bacon , Robert Crittenden