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Related papers: A new measure for cosmic shear

200 papers

With the developments of large galaxy surveys or cosmic shear surveys it is now possible to map the dark matter distribution at truly cosmological scales. Detailed examinations of the statistical properties of the dark matter distribution…

Astrophysics · Physics 2007-05-23 Francis Bernardeau

We present a Bayesian hierarchical modelling approach to infer the cosmic matter density field, and the lensing and the matter power spectra, from cosmic shear data. This method uses a physical model of cosmic structure formation to infer…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-03 Natalia Porqueres , Alan Heavens , Daniel Mortlock , Guilhem Lavaux

Cosmic shear measurements rely on our ability to measure and correct the Point Spread Function (PSF) of the observations. This PSF is measured using stars in the field, which give a noisy measure at random points in the field. Using Wiener…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 A. Amara , A. Refregier , S. Paulin-Henriksson

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…

In recent years cosmic shear, the weak gravitational lensing effect by the large-scale structure of the Universe, has proven to be one of the observational pillars on which the cosmological concordance model is founded. Several cosmic shear…

Astrophysics · Physics 2008-03-12 B. Joachimi , P. Schneider , T. Eifler

Context. Weak lensing and clustering statistics beyond two-point functions can capture non-Gaussian information about the matter density field, thereby improving the constraints on cosmological parameters relative to the mainstream methods…

The phenomenon of cosmic shear, or distortion of images of distant sources unaccompanied by magnification, is an effective way of probing the content and state of the foreground Universe, because light rays do not have to pass through mass…

Astrophysics · Physics 2009-11-13 Richard Lieu

Weak gravitational lensing has proven to be a powerful tool to map directly the distribution of dark matter in the Universe. The technique, currently used, relies on the accurate measurement of the gravitational shear that corresponds to…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 S. Pires , A. Amara

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

Astrophysics · Physics 2008-09-24 Sheng Wang , Zoltan Haiman , Morgan May , John Kehayias

Weak gravitational lensing provides a unique method to map directly the distribution of dark matter in the universe and to measure cosmological parameters. This cosmic-shear technique is based on the measurement of the weak distortions that…

Astrophysics · Physics 2008-11-26 Alexandre Refregier

Cosmic shear is one of the most powerful probes of Dark Energy, targeted by several current and future galaxy surveys. Lensing shear, however, is only sampled at the positions of galaxies with measured shapes in the catalog, making its…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-31 Andrina Nicola , Carlos García-García , David Alonso , Jo Dunkley , Pedro G. Ferreira , Anže Slosar , David N. Spergel

We study the accuracy with which weak lensing measurements could be made from a future space-based survey, predicting the subsequent precisions of 3-dimensional dark matter maps, projected 2-dimensional dark matter maps, and mass-selected…

We study various measures of weak lensing distortions in future surveys, taking into account the noise arising from the finite survey size and the intrinsic ellipticity of galaxies. We also consider a realistic redshift distribution of the…

Astrophysics · Physics 2009-11-10 Patrick Valageas , Dipak Munshi , Andrew J. Barber

Cosmic shear is a powerful probe of cosmological distances, matter abundance and clustering in the low-redshift Universe. Cosmological parameter extraction from cosmic shear data is limited by our understanding of baryonic astrophysics,…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-31 Shi-Fan Chen , Joseph DeRose , Mikhail M. Ivanov , Oliver H. E. Philcox

In this paper we describe the predictions for the smoothed weak lensing shear and aperture-mass of two simple analytical models of the density field: the minimal tree-model and the stellar model. Both models give identical results for the…

Astrophysics · Physics 2009-11-10 Dipak Munshi , Patrick Valageas , Andrew J. Barber

In the context of tomographic cosmic shear surveys, a theoretical model for the one-point statistics of the aperture mass (Map) is developed. This formalism is based on the application of the large deviation principle to the projected…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-07 Alexandre Barthelemy , Sandrine Codis , Francis Bernardeau

I present a new technique for the measurement of the growth of cosmic structures via the power spectrum of weak lensing cosmic shear. It is based on a template-fitting approach, where a redshift-dependent amplitude of lensing modulates a…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-09 Stefano Camera

The expansion of the universe causes spacetime curvature, distinguishing between distances measured along and transverse to the line of sight. The ratio of these distances, e.g. the cosmic shear distortion of a sphere defined by…

Astrophysics · Physics 2009-11-07 Eric V. Linder