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Cosmic shear data contains a large amount of cosmological information encapsulated in the non-Gaussian features of the weak lensing mass maps. This information can be extracted using non-Gaussian statistics. We compare the constraining…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-20 Dominik Zürcher , Janis Fluri , Raphael Sgier , Tomasz Kacprzak , Alexandre Refregier

The first half of this paper explores the origin of systematic biases in the measurement of weak gravitational lensing. Compared to previous work, we expand the investigation of PSF instability and fold in for the first time the effects of…

Context. The density split statistics in weak gravitational lensing analyses probes the correlation between regions of different (foreground) galaxy number densities and their weak lensing signal, measured by the shape distortion of…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-21 Pierre Burger , Peter Schneider , Vasiliy Demchenko , Joachim Harnois-Deraps , Catherine Heymans , Hendrik Hildebrandt , Sandra Unruh

We study cosmic shear statistics using the ray-tracing simulation combined with a set of large $N$-body simulations. In this contribution, we first describe our method. Then we show some selected results especially focusing on effects of…

Astrophysics · Physics 2009-10-31 Takashi Hamana , Stephane Colombi , Yannick Mellier

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

$ $Weak gravitational lensing is a powerful probe which is used to constrain the standard cosmological model and its extensions. With the enhanced statistical precision of current and upcoming surveys, high accuracy predictions for weak…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-26 Ting Tan , Dominik Zuercher , Janis Fluri , Alexandre Refregier , Federica Tarsitano , Tomasz Kacprzak

Halo masses and concentrations have been studied extensively, by means of N-body simulations as well as observationally, during the last decade. Nevertheless, the exact form of the mass-concentration relation is still widely debated. One of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Roberto Mainini , Anna Romano

The possibility of detecting weak lensing effects from deep wide field imaging surveys has open new means of probing the large-scale structures of the Universe and measuring cosmological parameters. In this paper we present a systematic…

Astrophysics · Physics 2010-04-06 F. Bernardeau , L. van Waerbeke , Y. Mellier

In many cosmological inference problems, the likelihood (the probability of the observed data as a function of the unknown parameters) is unknown or intractable. This necessitates approximations and assumptions, which can lead to incorrect…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-02 Niall Jeffrey , Justin Alsing , François Lanusse

Future weak lensing surveys will directly probe the density fluctuation in the universe. Recent studies have shown how the statistics of the weak lensing convergence field is related to the statistics of collapsed objects. Extending earlier…

Astrophysics · Physics 2008-11-26 Dipak Munshi

Cosmic shear tomography has emerged as one of the most promising tools to both investigate the nature of dark energy and discriminate between General Relativity and modified gravity theories. In order to successfully achieve these goals,…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-05 V. F. Cardone , M. Martinelli , E. Calabrese , S. Galli , Z. Huang , R. Maoli , A. Melchiorri , R. Scaramella

We investigate the impact of point spread function (PSF) fitting errors on cosmic shear measurements using the concepts of complexity and sparsity. Complexity, introduced in a previous paper, characterizes the number of degrees of freedom…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 S. Paulin-Henriksson , A. Refregier , A. Amara

We investigate the impact of the observed correlation between a galaxies shape and its surrounding density field on the measurement of third order weak lensing shear statistics. Using numerical simulations, we estimate the systematic error…

We propose to use a simple observable, the fractional area of "hot spots" in weak gravitational lensing mass maps which are detected with high significance, to determine background cosmological parameters. Because these high-convergence…

Astrophysics · Physics 2011-02-11 Sheng Wang , Zoltán Haiman , Morgan May

The Shear TEsting Programme (STEP) is a collaborative project to improve the accuracy and reliability of weak lensing measurement, in preparation for the next generation of wide-field surveys. We review sixteen current and emerging shear…

We investigate the information content of various cosmic shear statistics on the theory of gravity. Focusing on the Hu-Sawicki-type $f(R)$ model, we perform a set of ray-tracing simulations and measure the convergence bispectrum, peak…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-25 Masato Shirasaki , Takahiro Nishimichi , Baojiu Li , Yuichi Higuchi

Measurements of the shear induced by weak gravitational lensing around galaxy cluster lines of sight are the gold standard for calibrating cluster observable-mass relations, thereby enabling a robust and precise inference of cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-26 S. Bocquet , A. Fumagalli , C. T. Davies , K. Dolag , S. Grandis , J. J. Mohr

The deep imaging of the field of an observed lensing event by a cosmic string reveals many additional lensing events. We study the statistics of such string lensing. We derive explicit expressions for the distributions of image separations…

Astrophysics · Physics 2009-11-13 Masamune Oguri , Keitaro Takahashi

We describe a method for computing the biases that systematic signals introduce in parameter estimation using a simple extension of the Fisher matrix formalism. This allows us to calculate the offset of the best fit parameters relative to…

Astrophysics · Physics 2009-11-13 Adam Amara , Alexandre Refregier

We investigate the effect of weak gravitational lensing in the limit of small angular scales where projected galaxy clustering is strongly nonlinear. This is the regime likely to be probed by future weak lensing surveys. We use…

Astrophysics · Physics 2009-10-31 Dipak Munshi , Peter Coles