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Related papers: Post-Limber Weak Lensing Bispectrum, Reduced Shear…

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As recently shown by Viola et al., the common (KSB) method for measuring weak gravitational shear creates a non-linear relation between the measured and the true shear of objects. We investigate here what effect such a non-linear…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Matthias Bartelmann , Massimo Viola , Peter Melchior , Björn M. Schäfer

Cluster-scale strong lensing is a powerful tool for exploring the properties of dark matter and constraining cosmological models. However, due to the complex parameter space, pixelized strong lens modeling in galaxy clusters is…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-07 Yushan Xie , Huanyuan Shan , Nan Li , Ran Li , Eric Jullo , Chen Su , Xiaoyue Cao , Jean-Paul Kneib , Ana Acebron , Mengfan He , Ji Yao , Chunxiang Wang , Jiadong Li , Yin Li

The cosmic microwave background (CMB) bispectrum is a well-known probe of the non-Gaussianity of primordial perturbations. Just as the intervening large-scale structure modifies the CMB angular power spectrum through weak gravitational…

Astrophysics · Physics 2008-11-26 Asantha Cooray , Devdeep Sarkar , Paolo Serra

Weak gravitational lensing (WL) is a key cosmological probe that requires precise measurement of galaxy images to infer shape distortions, or shear, and constrain cosmology. Accurate estimation of the Point Spread Function (PSF) is crucial…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-28 Federico Berlfein , Rachel Mandelbaum , Xiangchong Li , Tianqing Zhang , Scott Dodelson , Katarina Markovic

In this paper we show how response function corrections to shear measurements (e.g. as required by Metacalibration) propagate into cosmic shear power spectra. We investigate a 2-sphere pixel (also known as HEALpixel') correction and a…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-01 T. D. Kitching , N. Tessore , P. L. Taylor

This article constructs flat-sky approximations in a controlled way in the context of the cosmic microwave background observations for the computation of both spectra and bispectra. For angular spectra, it is explicitly shown that there…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Francis Bernardeau , Cyril Pitrou , Jean-Philippe Uzan

Forthcoming projects such as DES, LSST, WFIRST, and Euclid aim to measure weak lensing shear correlations with unprecedented precision, constraining the dark energy equation of state at the percent level. Reliance on…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Andrew P. Hearin , Andrew R. Zentner , Zhaoming Ma

We revisit the estimation of higher order corrections to the angular power spectra of weak gravitational lensing. Extending a previous calculation of Cooray and Hu, we find two additional terms to the fourth order in potential perturbations…

Astrophysics · Physics 2011-05-12 Charles Shapiro , Asantha Cooray

The precision of Stage IV cosmic shear surveys will enable us to probe smaller physical scales than ever before, however, model uncertainties from baryonic physics and non-linear structure formation will become a significant concern. The…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-27 Anurag C. Deshpande , Peter L. Taylor , Thomas D. Kitching

The potential of cosmic shear to probe cosmology is well recognized and future optical wide field surveys are currently being designed to optimize the return of cosmic shear science. High precision cosmic shear analysis requires high…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 L. Van Waerbeke

[Abridged] We seek approximations to the cosmic shear covariance that are as easy to use as the common approximations based on normal statistics, but yield more accurate covariance matrices and parameter errors. We derive expressions for…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Stefan Hilbert , Jan Hartlap , Peter Schneider

Weak-lensing shear estimates show a troublesome dependence on the apparent brightness of the galaxies used to measure the ellipticity: In several studies, the amplitude of the inferred shear falls sharply with decreasing source…

Instrumentation and Methods for Astrophysics · Physics 2012-11-26 Peter Melchior , Massimo Viola

We examine the cosmological constraining power of future large-scale weak lensing surveys on the model of \emph{Euclid}, with particular reference to primordial non-Gaussianity. Our analysis considers several different estimators of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 C. Fedeli , M. Bartelmann , L. Moscardini

Upcoming surveys such as \LSST{} and \Euclid{} will significantly improve the power of weak lensing as a cosmological probe. To maximise the information that can be extracted from these surveys, it is important to explore novel statistics…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-18 Christopher T. Davies , Marius Cautun , Benjamin Giblin , Baojiu Li , Joachim Harnois-Déraps , Yan-Chuan Cai

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…

We present SKiLLS, a suite of multi-band image simulations for the weak lensing analysis of the complete Kilo-Degree Survey (KiDS), dubbed KiDS-Legacy analysis. The resulting catalogues enable joint shear and redshift calibration, enhancing…

Precise reconstruction of the cosmic microwave background lensing potential can be achieved with deep polarization surveys by iteratively removing lensing-induced $B$ modes. We introduce a lensing spectrum estimator and its likelihood for…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-13 Louis Legrand , Julien Carron

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

In this paper we revisit potential biases in cosmic shear power spectra caused by bias terms that multiply up to quadratic powers of the shear. Expanding the multiplicative bias field as a series of independent spin-$s$ fields we find terms…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-31 T. D. Kitching , A. C. Deshpande

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…

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