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We study how well the Gaussian approximation is valid for computing the covariance matrices of the convergence power and bispectrum in weak gravitational lensing analyses. We focus on its impact on the cosmological parameter estimations by…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Masanori Sato , Takahiro Nishimichi

In this third paper of a series on radio weak lensing for cosmology with the Square Kilometre Array, we scrutinise synergies between cosmic shear measurements in the radio and optical/near-IR bands for mitigating systematic effects. We…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-19 Stefano Camera , Ian Harrison , Anna Bonaldi , Michael L. Brown

We present a cosmic shear analysis of the 100 square degree weak lensing survey, combining data from the CFHTLS-Wide, RCS, VIRMOS-DESCART and GaBoDS surveys. Spanning ~100 square degrees, with a median source redshift z~0.78, this combined…

Using separate universe simulations, we accurately quantify super-sample covariance (SSC), the typically dominant sampling error for matter power spectrum estimators in a finite volume, which arises from the presence of super survey modes.…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-28 Yin Li , Wayne Hu , Masahiro Takada

Accurate inference of cosmology from weak lensing shear requires an accurate shear power spectrum covariance matrix. Here, we investigate this accuracy requirement and quantify the relative importance of the Gaussian (G), super-sample…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-20 Alexandre Barreira , Elisabeth Krause , Fabian Schmidt

Analytical expressions for covariances of weak lensing statistics related to the aperture mass $\Map$ are derived for realistic survey geometries such as SNAP for a range of smoothing angles and redshift bins. We incorporate the…

Astrophysics · Physics 2009-11-10 Dipak Munshi , Patrick Valageas

Cosmic shear is a powerful method to constrain cosmology, provided that any systematic effects are under control. The intrinsic alignment of galaxies is expected to severely bias parameter estimates if not taken into account. We explore the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 B. Joachimi , S. L. Bridle

We present the first calculation of the cross-correlation between three-dimensional cosmic shear and the integrated Sachs-Wolfe (iSW) effect. Both signals are combined in a single formalism, which permits the computation of the full…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-22 Britta Zieser , Philipp M. Merkel

We estimate and remove the contamination of weak gravitational lensing measurements by the intrinsic alignment of close pairs of galaxies. We do this by investigating both the aperture mass B mode statistic, and the shear correlations of…

We study the effect of super-sample covariance (SSC) on the power spectrum and higher-order statistics: bispectrum, halo mass function, and void size function. We also investigate the effect of SSC on the cross covariance between the…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-17 Adrian E. Bayer , Jia Liu , Ryo Terasawa , Alexandre Barreira , Yici Zhong , Yu Feng

We investigate correlations induced by gravitational lensing on simulated cosmic microwave background data of experiments with an incomplete sky coverage and their effect on inferences from the South Pole Telescope data. These correlations…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-09 Pavel Motloch , Wayne Hu

Intrinsic alignments constitute the major astrophysical systematic for cosmological weak lensing surveys. We present a purely geometrical method with which one can study gravitational shear-intrinsic ellipticity correlations directly in…

Cosmology and Nongalactic Astrophysics · Physics 2010-08-23 B. Joachimi , P. Schneider

As weak lensing surveys go deeper, there is an increasing need for reliable characterization of non-Gaussian structures at small angular scales. Here we present the first cosmological constraints with weak lensing scattering transform, a…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-12 Sihao Cheng , Gabriela A. Marques , Daniela Grandón , Leander Thiele , Masato Shirasaki , Brice Ménard , Jia Liu

Data analysis from upcoming large galaxy redshift surveys, such as Euclid and DESI will significantly improve constraints on cosmological parameters. To optimally extract the information from these galaxy surveys, it is important to control…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-22 S. Gouyou Beauchamps , P. Baratta , S. Escoffier , W. Gillard , J. Bel , J. Bautista , C. Carbone

Recent cosmic shear analyses have exhibited discrepancies of up to $1\sigma$ between the inferred cosmological parameters when analyzing summary statistics in real space versus harmonic space. In this paper, we demonstrate the consistent…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-23 Andy Park , Sukhdeep Singh , Xiangchong Li , Rachel Mandelbaum , Tianqing Zhang

Upcoming wide-area weak lensing surveys are expensive both in time and cost and require an optimal survey design in order to attain maximum scientific returns from a fixed amount of available telescope time. The super-sample covariance…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Ryuichi Takahashi , Shunji Soma , Masahiro Takada , Issha Kayo

The cosmological interpretation of weak lensing by large-scale structures requires knowledge of the redshift distribution of the source galaxies. Current lensing surveys are often calibrated using external redshift samples which span a…

Astrophysics · Physics 2008-11-26 Ludovic Van Waerbeke , Martin White , Henk Hoekstra , Catherine Heymans

Cosmic shear surveys have great promise as tools for precision cosmology, but can be subject to systematic errors including intrinsic ellipticity correlations of the source galaxies. The intrinsic alignments are believed to be small for…

Astrophysics · Physics 2010-10-28 Christopher M. Hirata , Uros Seljak

We present a numerically cheap approximation to super-sample covariance (SSC) of large scale structure cosmological probes, first in the case of angular power spectra. It necessitates no new elements besides those used for the prediction of…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-17 Fabien Lacasa , Julien Grain

The current methods available to estimate gravitational shear from astronomical images of galaxies introduce systematic errors which can affect the accuracy of weak lensing cosmological constraints. We study the impact of KSB shape…