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Related papers: Cosmic shear covariance: The log-normal approximat…

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We explore a variety of statistics of clusters selected with cosmic shear measurement by utilizing both analytic models and large numerical simulations. We first develop a halo model to predict the abundance and the clustering of weak…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-16 Masato Shirasaki , Takashi Hamana , Naoki Yoshida

Exploiting the full statistical power of future cosmic shear surveys will necessitate improvements to the accuracy with which the gravitational lensing signal is measured. We present a framework for calibrating shear with image simulations…

In order to reach the required performance of Stage-III and IV weak lensing surveys, cosmic shear measurements have to rely on external simulations to calibrate residual biases. Over the years, several techniques have been developed to…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-11 G. Congedo , A. N. Taylor

We present a combined cosmic shear analysis of the modeling of line-of-sight distortions on strongly lensed extended arcs and galaxy shape measurements in the COSMOS field. We develop a framework to predict the covariance of strong lensing…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-14 Felix Arjun Kuhn , Claudio Bruderer , Simon Birrer , Adam Amara , Alexandre Réfrégier

Statistical weak lensing by large-scale structure -- cosmic shear -- is a promising cosmological tool, which has motivated the design of several large upcoming surveys. Here, we present a measurement of cosmic shear using coadded Sloan…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-15 Eric M. Huff , Tim Eifler , Christopher M. Hirata , Rachel Mandelbaum , David Schlegel , Uros Seljak

Cosmological analyses of second-order weak lensing statistics require precise and accurate covariance estimates. These covariances are impacted by two sometimes neglected terms: A negative contribution to the Gaussian covariance due to…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-04 Laila Linke , Pierre A. Burger , Sven Heydenreich , Lucas Porth , Peter Schneider

The ratio of the average tangential shear signal of different weak lensing source populations around the same lens galaxies, also known as a shear ratio, provides an important test of lensing systematics and a potential source of…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-01 Ni Emas , Chris Blake , Rossana Ruggeri , Anna Porredon

We present here the cosmo-SLICS, a new suite of simulations specially designed for the analysis of current and upcoming weak lensing data beyond the standard two-point cosmic shear. We sample the $[\Omega_{\rm m}, \sigma_8, h, w_0]$…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-20 Joachim Harnois-Deraps , Benjamin Giblin , Benjamin Joachimi

We identify and study a previously unknown systematic effect on cosmic shear measurements, caused by the selection of galaxies used for shape measurement, in particular the rejection of close (blended) galaxy pairs. We use ray-tracing…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Jan Hartlap , Stefan Hilbert , Peter Schneider , Hendrik Hildebrandt

Cosmological observables rely heavily on summary statistics such as two-point correlation functions. In many practical cases (e.g. the weak-lensing cosmic shear), those correlation functions are estimated from a finite, discrete sample of…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-24 Pierre Fleury

Covariance matrices are important tools for obtaining reliable parameter constraints. Advancements in cosmological surveys lead to larger data vectors and, consequently, increasingly complex covariance matrices, whose number of elements…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-31 Tassia Ferreira , Valerio Marra

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

Focusing on the well motivated aperture mass statistics $\Map$, we study the possibility of constraining cosmological parameters using future space based SNAP class weak lensing missions. Using completely analytical results we construct the…

Astrophysics · Physics 2007-05-23 Dipak Munshi , Patrick Valageas

Weak-lensing searches for galaxy clusters are plagued by low completeness and purity, severely limiting their usefulness for constraining cosmological parameters with the cluster mass function. A significant fraction of `false positives'…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 J. P. Dietrich , J. Hartlap

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

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…

Context. Gravitational lensing is one of the leading tools in understanding the dark side of the Universe. The need for accurate, efficient and effective methods which are able to extract this information along with other cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Marika Asgari , Peter Schneider , Patrick Simon

Owing to the mass-sheet degeneracy, cosmic shear maps do not probe directly the Fourier modes of the underlying mass distribution on scales comparable to the survey size and larger. To assess the corresponding effect on attainable…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Julien Carron , István Szapudi

Weak gravitational lensing surveys are rapidly becoming important tools to probe directly the mass density fluctuations in the universe and its background dynamics. Earlier studies have shown that it is possible to model the statistics of…

Astrophysics · Physics 2009-11-07 Patrick Valageas , Andrew J. Barber , Dipak Munshi

We present the application of the pseudo-spectrum method to galaxy-galaxy lensing. We derive explicit expressions for the pseudo-spectrum analysis of the galaxy-shear cross spectrum, which is the Fourier space counterpart of the stacked…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-25 Chiaki Hikage , Masamune Oguri