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Weak lensing of CMB anisotropies and polarization for the power spectra and higher order statistics can be handled directly in harmonic-space without recourse to real-space correlation functions. For the power spectra, this approach not…

Astrophysics · Physics 2009-10-31 Wayne Hu

Reconstruction of the linear power spectrum from observational data provides a way to compare cosmological models to a large amount of data, as Peacock & Dodds (1994, 1996) have shown. By applying the appropriate corrections to the…

Astrophysics · Physics 2009-10-30 Clay Smith , Anatoly Klypin , Michael Gross , Joel Primack , Jon Holtzman

The disconnected part of the power spectrum covariance matrix (also known as the "Gaussian" covariance) is the dominant contribution on large scales for galaxy clustering and weak lensing datasets. The presence of a complicated sky mask…

Cosmology and Nongalactic Astrophysics · Physics 2019-12-02 Carlos García-García , David Alonso , Emilio Bellini

Galaxy-galaxy weak lensing provides a powerful means of measuring the average matter distribution around lens galaxies -- i.e., the galaxy bias relation. Properly accounting for the spin-2 nature of weak lensing distortions, we develop a…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-28 Taisei Terawaki , Masahiro Takada , Takanori Taniguchi

We present the application of the pseudo-spectrum method to galaxy-galaxy lensing. We derive explicit expressions for the pseudo-spectrum analysis of the galaxy-shear cross spectrum, which is the Fourier space counterpart of the stacked…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-25 Chiaki Hikage , Masamune Oguri

Weak lensing shear estimation typically results in per galaxy statistical errors significantly larger than the sought after gravitational signal of only a few percent. These statistical errors are mostly a result of shape-noise -- an…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-08 Ofer M. Springer , Eran O. Ofek , Yair Weiss , Julian Merten

We use statistical inference theory to explore the constraints from future galaxy weak lensing (cosmic shear) surveys combined with the current CMB constraints on cosmological parameters, focusing particularly on the running of the spectral…

Astrophysics · Physics 2009-11-10 Mustapha Ishak , Christopher M. Hirata , Patrick McDonald , Uros Seljak

I present a new algorithm, CALCLENS, for efficiently computing weak gravitational lensing shear signals from large N-body light cone simulations over a curved sky. This new algorithm properly accounts for the sky curvature and boundary…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-15 Matthew R. Becker

Weak lensing, which is the deflection of light by matter along the line of sight, has proven to be an efficient method for constraining models of structure formation and reveal the nature of dark energy. So far, most weak-lensing studies…

Weak gravitational lensing allows one to reconstruct the spatial distribution of the projected mass density across the sky. These "mass maps" provide a powerful tool for studying cosmology as they probe both luminous and dark matter. In…

We investigate the prospects for using the weak lensing bispectrum alongside the power spectrum to control systematic uncertainties in a Euclid-like survey. Three systematic effects are considered: the intrinsic alignment of galaxies,…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-02 Susan Pyne , Benjamin Joachimi

We measure seeing-corrected ellipticities for 2 x 10^6 galaxies with magnitude R<23 in 12 widely separated fields totalling 75 deg^2 of sky. At angular scales >30\arcmin, ellipticity correlations are detected at high significance and…

Astrophysics · Physics 2015-06-24 M. Jarvis , G. Bernstein , B. Jain , P. Fischer , D. Smith , J. A. Tyson , D. Wittman

A primary goal of galaxy surveys is to tighten constraints on cosmological parameters, and the power spectrum $P(k)$ is the standard means of doing so. However, at translinear scales $P(k)$ is blind to much of these surveys'…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-31 Andrew Repp , István Szapudi

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

Modifications of the matter power spectrum due to baryonic physics are one of the major theoretical uncertainties in cosmological weak lensing measurements. Developing robust mitigation schemes for this source of systematic uncertainty…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-21 Hung-Jin Huang , Tim Eifler , Rachel Mandelbaum , Scott Dodelson

Forthcoming galaxy surveys will provide measurements of galaxy clustering with an unprecedented level of precision, that will require comparably good accuracy. Current models for galaxy correlations rely on approximations and idealizations…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-26 Alvise Raccanelli , Zvonimir Vlah

Weak lensing of the CMB changes the unlensed temperature anisotropy and polarization power spectra. Accounting for the lensing effect will be crucial to obtain accurate parameter constraints from sensitive CMB observations. Methods for…

Astrophysics · Physics 2009-11-10 Anthony Challinor , Antony Lewis

Estimation of the angular power spectrum of the Cosmic Microwave Background (CMB) on a small patch of sky is usually plagued by serious spectral leakage, specially when the map has a hard edge. Even on a full sky map, point source masks can…

Astrophysics · Physics 2009-11-06 Sudeep Das , Amir Hajian , David N. Spergel

We review the effect of the commonly-used Limber and flat-sky approximations on the calculation of shear power spectra and correlation functions for galaxy weak lensing. These approximations are accurate at small scales, but it has been…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-17 Pablo Lemos , Anthony Challinor , George Efstathiou

This paper presents the results of a systematic study of projection biases in the Weak Lensing analysis of cosmic shear and the combination of galaxy clustering and galaxy-galaxy lensing using data collected during the first-year of running…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-27 P. R. V. Chintalapati , G. Gutierrez , M. H. L. S. Wang