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Related papers: Cosmic Shear Statistics and Cosmology

200 papers

Cosmic shear measurements have now improved to the point where they deserve to be treated on par with CMB and galaxy clustering data for cosmological parameter analysis, using the full measured aperture mass variance curve rather than a…

Astrophysics · Physics 2009-10-07 Xiaomin Wang , Max Tegmark , Bhuvnesh Jain , Matias Zaldarriaga

We present a measurement of cosmic shear on scales ranging from $ 10\arcsec $ to $ 2\arcmin $ in 347 WFPC2 images of random fields. Our result is based on shapes measured via image fitting and on a simple statistical technique; careful…

Astrophysics · Physics 2009-11-10 Stefano Casertano , Kavan U. Ratnatunga , Richard E. Griffiths

With the advent of large-scale weak lensing surveys there is a need to understand how realistic, scale-dependent systematics bias cosmic shear and dark energy measurements, and how they can be removed. Here we describe how spatial…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-31 A. N. Taylor , T. D. Kitching

We report on the marginal detection of cosmic shear on sub-arcmin scales with archive data from the STIS camera on board HST. For the measurement 121 galaxy fields with a field of view of 51'' x 51'' are used to obtain an rms cosmic shear…

Studies of weak gravitational lensing by large-scale structures require the measurement of the distortions introduced to the shapes of distant galaxies at the few percent level by anisotropic light deflection along the line of sight. To…

Astrophysics · Physics 2009-11-07 Andrew W. Blain

We study the statistics of peaks in a weak lensing reconstructed mass map of the first 450 square degrees of the Kilo Degree Survey. The map is computed with aperture masses directly applied to the shear field with an NFW-like compensated…

Weak gravitational lensing provides a direct statistical measure of the dark matter distribution. The variance is easiest to measure, which constrains the degenerate product \sigma_8\Omega^0.6. The degeneracy is broken by measuring the…

The correlation between cosmic shear as measured by the image distortion of high-redshift galaxies and the number counts of foreground galaxies is calculated. For a given power spectrum of the cosmic density fluctuations, this correlation…

Astrophysics · Physics 2009-10-30 Peter Schneider

We present a reanalysis of the VIRMOS-Descart weak lensing data, with a particular focus on different corrections for the variation of the point spread function anisotropy (PSF) across the CCDs. We show that the small scale systematics can…

Astrophysics · Physics 2009-11-10 L. Van Waerbeke , Y. Mellier , H. Hoekstra

We present a method to measure the growth of structure and the background geometry of the Universe -- with no a priori assumption about the underlying cosmological model. Using Canada-France-Hawaii Lensing Survey (CFHTLenS) shear data we…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-12 Peter L. Taylor , Thomas D. Kitching , Jason D. McEwen

We present a field-based approach to the analysis of cosmic shear data to infer jointly cosmological parameters and the dark matter distribution. This forward modelling approach samples the cosmological parameters and the initial matter…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-17 Natalia Porqueres , Alan Heavens , Daniel Mortlock , Guilhem Lavaux

We constrain cosmological parameters from a joint cosmic shear analysis of peak-counts and the two-point shear correlation functions, as measured from the Dark Energy Survey (DES-Y1). We find the structure growth parameter $S_8\equiv…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-14 Joachim Harnois-Déraps , Nicolas Martinet , Tiago Castro , Klaus Dolag , Benjamin Giblin , Catherine Heymans , Hendrik Hildebrandt , Qianli Xia

We explore the scale and angular dependence of the cosmic shear three-point correlation function. The shear field is found to have a much more complex three-point function than the convergence field, but it also exhibits specific motifs…

Astrophysics · Physics 2009-11-07 F. Bernardeau , L. van Waerbeke , Y. Mellier

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 present the galaxy shear catalog that will be used for the three-year cosmological weak gravitational lensing analyses using data from the Wide layer of the Hyper Suprime-Cam (HSC) Subaru Strategic Program (SSP) Survey. The galaxy shapes…

We report on the detection of cosmic shear on angular scales of 1.3-6.5 arcmin using 45 independent empty fields observed with the Very Large Telescope (VLT). This result confirms previous measurements obtained with the CFH Telescope at the…

Astrophysics · Physics 2007-05-23 R. Maoli , Y. Mellier , L. van Waerbeke , P. Schneider , B. Jain , T. Erben , F. Bernardeau , B. Fort Fort

We present an 8 sigma detection of cosmic magnification measured by the variation of quasar density due to gravitational lensing by foreground large scale structure. To make this measurement we used 3800 square degrees of photometric…

Residual errors in shear measurements, after corrections for instrument systematics and atmospheric effects, can impact cosmological parameters derived from weak lensing observations. Here we combine convergence maps from our suite of…

Cosmology and Nongalactic Astrophysics · Physics 2015-01-06 Andrea Petri , Morgan May , Zoltan Haiman , Jan M. Kratochvil

Weak lensing by large-scale structure provides a unique method to directly measure matter fluctuations in the universe, and has recently been detected from the ground. Here, we report the first detection of this `cosmic shear' based on…

Astrophysics · Physics 2009-11-06 J. Rhodes , A. Refregier , E. J. Groth

We present a direct detection of the growth of large-scale structure, using weak gravitational lensing and photometric redshift data from the COMBO-17 survey. We use deep R-band imaging of two 0.25 square degree fields, affording shear…