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We develop a pseudo power spectrum technique for measuring the lensing power spectrum from weak lensing surveys in both the full sky and flat sky limits. The power spectrum approaches have a number of advantages over the traditional…

Cosmology and Nongalactic Astrophysics · Physics 2011-04-06 Chiaki Hikage , Masahiro Takada , Takashi Hamana , David Spergel

We present a field-based signal extraction of weak lensing from noisy observations on the curved and masked sky. We test the analysis on a simulated Euclid-like survey, using a Euclid-like mask and noise level. To make optimal use of the…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-09 A. Loureiro , L. Whiteway , E. Sellentin , J. S. Lafaurie , A. H. Jaffe , A. F. Heavens

We apply a mass reconstruction technique to simulated large-scale structure gravitational distortion maps, from 2.5' to 10 degree scales, for different cosmological scenarii. The projected mass is reconstructed using a non-parametric least…

Astrophysics · Physics 2007-05-23 L. Van Waerbeke , F. Bernardeau , Y. Mellier

We revisit the flat-sky approximation for evaluating the angular power spectra of projected random fields by retaining information about the correlations along the line of sight. With broad, overlapping radial window functions, these…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-16 Zucheng Gao , Zvonimir Vlah , Anthony Challinor

With the steadily improving sensitivity afforded by current and future galaxy surveys, a robust extraction of two-point correlation function measurements may become increasingly hampered by the presence of astrophysical foregrounds or…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-21 Franz Elsner , Boris Leistedt , Hiranya V. Peiris

We show, using the pseudo-$C_\ell$ technique, how to estimate cosmic shear and galaxy-galaxy lensing power spectra that are insensitive to the effects of multiple sources of lensing bias including source-lens clustering, magnification bias…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-12 Christopher A. J. Duncan , Michael L. Brown

We present a survey of the cosmological applications of the next generation of weak lensing surveys, paying special attention to the computational challenges presented by the number of galaxies, $N_{gal} ~$ 10$^{5}$. We focus on optimal…

Astrophysics · Physics 2009-11-07 N. Padmanabhan , U. Seljak , U. L. Pen

Headline constraints on cosmological parameters from current weak lensing surveys are derived from two-point statistics that are known to be statistically sub-optimal, even in the case of Gaussian fields. We study the performance of a new…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-15 Alessandro Maraio , Alex Hall , Andy Taylor

We develop a method for estimating the shear power spectra from weak lensing observations and test it on simulated data. Our method describes the shear field in terms of angular power spectra and cross correlation of the two shear modes…

Astrophysics · Physics 2008-11-26 Wayne Hu , Martin White

The statistics of shear peaks have been shown to provide valuable cosmological information beyond the power spectrum, and will be an important constraint of models of cosmology with the large survey areas provided by forthcoming…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-15 Deborah Bard , Jan M. Kratochvil , William Dawson

The widely used MASTER approach for angular power spectrum estimation was developed as a fast $C_{\ell}$ estimator on limited regions of the sky. This method expresses the power spectrum of a masked map ("pseudo-$C_\ell$") in terms of the…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-27 Kristen M. Surrao , Oliver H. E. Philcox , J. Colin Hill

This paper presents the first application of 3D cosmic shear to a wide-field weak lensing survey. 3D cosmic shear is a technique that analyses weak lensing in three dimensions using a spherical harmonic approach, and does not bin data in…

We present a joint weak lensing and X-ray analysis of 4 deg$^2$ from the CFHTLS and XMM-LSS surveys. Our weak lensing analysis is the first analysis of a real survey using shapelets, a new generation weak lensing analysis method. We create…

We explore a variety of statistics of clusters selected with cosmic shear measurement by utilizing both analytic models and large numerical simulations. We first develop a halo model to predict the abundance and the clustering of weak…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-16 Masato Shirasaki , Takashi Hamana , Naoki Yoshida

Based on realistic simulations, we propose an hybrid method to reconstruct the lensing potential power spectrum, directly on PLANCK-like CMB frequency maps. It implies using a large galactic mask and dealing with a strong inhomogeneous…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-20 S. Plaszczynski , A. Lavabre , L. Perotto , J. -L. Starck

An accurate covariance matrix is essential for obtaining reliable cosmological results when using a Gaussian likelihood. In this paper we study the covariance of pseudo-$C_\ell$ estimates of tomographic cosmic shear power spectra. Using two…

We consider the bias introduced by a spatially-varying multiplicative shear bias (m-bias) on tomographic cosmic shear angular power spectra. To compute the bias in the power spectra, we estimate the mode-coupling matrix associated with an…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-30 Casey Cragg , Christopher A. J. Duncan , Lance Miller , David Alonso

We compute the spherical-sky weak-lensing power spectrum of the shear and convergence. We discuss various approximations, such as flat-sky, and first- and second- order Limber equations for the projection. We find that the impact of…

We study the lensing convergence power spectrum and its covariance for a standard LCDM cosmology. We run 400 cosmological N-body simulations and use the outputs to perform a total of 1000 independent ray-tracing simulations. We compare the…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-12 Masanori Sato , Takashi Hamana , Ryuichi Takahashi , Masahiro Takada , Naoki Yoshida , Takahiko Matsubara , Naoshi Sugiyama

Weak Gravitational Lensing is a powerful probe of the dark sector of the Universe. One of the main challenges for this technique is the treatment of systematics in the measurement of cosmic shear from galaxy shapes. In an earlier work,…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-15 Claudio Bruderer , Andrina Nicola , Adam Amara , Alexandre Refregier , Jörg Herbel , Tomasz Kacprzak
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