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Related papers: Cosmic Shear Tomography and Efficient Data Compres…

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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

We develop a Bayesian hierarchical modelling approach for cosmic shear power spectrum inference, jointly sampling from the posterior distribution of the cosmic shear field and its (tomographic) power spectra. Inference of the shear power…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-11 Justin Alsing , Alan Heavens , Andrew H. Jaffe , Alina Kiessling , Benjamin Wandelt , Till Hoffmann

Yes! Upcoming galaxy shear surveys have the potential to significantly improve our understanding of dark energy and neutrino mass if lensing systematics can be sufficiently controlled. The cross-correlations between the weak lensing shear,…

Cosmology and Nongalactic Astrophysics · Physics 2013-11-12 Sudeep Das , Josquin Errard , David Spergel

We explore the stability of the variance and skewness of the cosmic gravitational convergence field, using two different approaches: first we simulate a whole MEGACAM survey (100 sq. degrees). The reconstructed mass map, obtained from a…

Astrophysics · Physics 2007-05-23 A. Thion , Y. Mellier , F. Bernardeau , E. Bertin , T. Erben , L. van Waerbeke

Data re-sampling methods such as the delete-one jackknife are a common tool for estimating the covariance of large scale structure probes. In this paper we investigate the concepts of internal covariance estimation in the context of cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-10 O. Friedrich , S. Seitz , T. F. Eifler , D. Gruen

We apply two Bayesian hierarchical inference schemes to infer shear power spectra, shear maps and cosmological parameters from the CFHTLenS weak lensing survey - the first application of this method to data. In the first approach, we sample…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-10 Justin Alsing , Alan F. Heavens , Andrew H. Jaffe

During the past few years, secure detections of cosmic shear have been obtained, manifest in the correlation of the observed ellipticities of galaxies. Constraints have already been placed on cosmological parameters, such as the…

Astrophysics · Physics 2009-11-07 Lindsay King , Peter Schneider

Recently, it has been shown that cross-correlating CMB lensing and 3D cosmic shear allows to considerably tighten cosmological parameter constraints. We investigate whether similar improvement can be achieved in a conventional tomographic…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-27 Philipp M. Merkel , Bjoern Malte Schaefer

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

Aims. We quantify the mixing of the measured cosmic-shear E- and B-modes caused by the lack of shear-correlation measurements on small and large scales, arising from a lack of close projected galaxy pairs and the finite field size,…

Astrophysics · Physics 2016-08-30 Martin Kilbinger , Peter Schneider , Tim Eifler

UNIONS is an ongoing collaboration that will provide the largest deep photometric survey of the Northern sky in four optical bands to date. As part of this collaboration, CFIS is taking $r$-band data with an average seeing of 0.65 arcsec,…

Owing to their more extensive sky coverage and tighter control on systematic errors, future deep weak lensing surveys should provide a better statistical picture of the dark matter clustering beyond the level of the power spectrum. In this…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Dipak Munshi , Joseph Smidt , Alan Heavens , Peter Coles , Asantha Cooray

Measurements of weak gravitational lensing using the cosmic microwave background and the shapes of galaxies have refined our understanding of the late-time history of the Universe. While optical surveys have been the primary source for…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-20 Alba Kalaja , Ian Harrison , William R Coulton

Weak gravitational lensing of distant galaxies by foreground structures has proven to be a powerful tool to study the mass distribution in the universe. The advent of panoramic cameras on 4m class telescope has led to a first generation of…

Astrophysics · Physics 2019-10-23 Henk Hoekstra

We describe a new method for reducing the shape noise in weak lensing measurements by an order of magnitude. Our method relies on spectroscopic measurements of disk galaxy rotation and makes use of the Tully-Fisher relation in order to…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-11 Eric M. Huff , Elisabeth Krause , Tim Eifler , Xiao Fang , Matthew R. George , David Schlegel

(Abridged) Weak gravitational lensing induces distortions on the images of background galaxies, and thus provides a direct measure of mass fluctuations in the universe. Since the distortions induced by lensing on the images of background…

Astrophysics · Physics 2009-10-31 David Bacon , Alexandre Refregier , Douglas Clowe , Richard Ellis

The light we observe from distant astrophysical objects including supernovae and quasars allows us to determine large distances in terms of a cosmological model. Despite the success of the standard cosmological model in fitting the data,…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-07 Angela L. H. Ng

Gravitational lensing by large-scale structure induces weak coherent alignments in the shapes of background galaxies. Here we present evidence for the detection of this `cosmic shear' at the 3.4 sigma significance level with the William…

Astrophysics · Physics 2007-05-23 David Bacon , Alexandre Refregier , Richard Ellis