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We introduce a novel approach to reconstruct dark matter mass maps from weak gravitational lensing measurements. The cornerstone of the proposed method lies in a new modelling of the matter density field in the Universe as a mixture of two…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-26 J. -L. Starck , K. E. Themelis , N. Jeffrey , A. Peel , F. Lanusse

Calibrating the photometric redshifts of >10^9 galaxies for upcoming weak lensing cosmology experiments is a major challenge for the astrophysics community. The path to obtaining the required spectroscopic redshifts for training and…

We explore the dependence of weak lensing phenomena on the background cosmology. We first generalise the relation between $P_\psi(\omega)$, the angular power spectrum of the distortion, and the power spectrum of density fluctuations to…

Astrophysics · Physics 2009-10-28 Nick Kaiser

The weak gravitational lensing distortion of distant galaxy images (defined as sources) probes the projected large-scale matter distribution in the Universe. To improve quality in the 3D mass mapping using 3D-lensing, we combine the lensing…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Patrick Simon

From the nature of dark matter to the rate of expansion of our Universe, observations of distant galaxies distorted through strong gravitational lensing have the potential to answer some of the major open questions in astrophysics. Modeling…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-18 Siddharth Mishra-Sharma , Ge Yang

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

We present a Bayesian reconstruction method which maps a galaxy distribution from redshift-space to real-space inferring the distances of the individual galaxies. The method is based on sampling density fields assuming a lognormal prior…

We infer gravitational lensing shear and convergence fields from galaxy ellipticity catalogs under a spatial process prior for the lensing potential. We demonstrate the performance of our algorithm with simulated Gaussian-distributed…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-19 Michael D. Schneider , Karen Y. Ng , William A. Dawson , Philip J. Marshall , Joshua Meyers , Deborah J. Bard

We explore three different methods based on weak lensing to extract cosmological constraints from the large-scale structure. In the first approach (method I), small-scale galaxy lensing measurements of their halo mass provide a constraint…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Jaiyul Yoo , Uros Seljak

Dark matter halos represent the highest density peaks in the matter distribution. Conversely, cosmic voids are under-dense patches of the universe. Probing the mass distribution of the universe requires various approaches, including weak…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-09 Md Rasel Hossen , Sonia Akter Ema , Krzysztof Bolejko , Geraint F. Lewis

As deeper observations discover increasingly distant galaxies, characterizing the properties of high-redshift galaxy populations will become increasingly challenging and paramount. We present a method for measuring the clustering bias of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Brant E. Robertson

This paper presents the first application of 3D cosmic shear to a wide-field weak lensing survey. 3D cosmic shear is a technique that analyses weak lensing in three dimensions using a spherical harmonic approach, and does not bin data in…

We present a new method that simultaneously solves for cosmology and galaxy bias on non-linear scales. The method uses the halo model to analytically describe the (non-linear) matter distribution, and the conditional luminosity function…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Frank van den Bosch , Surhud More , Marcello Cacciato , Houjun Mo , Xiaohu Yang

We present a method that accurately propagates residual uncertainties in photometric redshift distributions into the cosmological inference from weak lensing measurements. The redshift distributions of tomographic redshift bins are…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-23 B. Stölzner , B. Joachimi , A. Korn , H. Hildebrandt , A. H. Wright

Galaxy clusters are one of the most powerful probes to study extensions of General Relativity and the Standard Cosmological Model. Upcoming surveys like the Vera Rubin Observatory's Legacy Survey of Space and Time are expected to…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-19 Markus Michael Rau , Florian Kéruzoré , Nesar Ramachandra , Lindsey Bleem

Weak lensing measurements are starting to provide statistical maps of the distribution of matter in the universe that are increasingly precise and complementary to cosmic microwave background maps. The probability distribution (PDF)…

Astrophysics · Physics 2009-11-10 Tong-Jie Zhang , Ue-Li Pen

We present a new method for measuring the projected mass distributions of galaxy clusters. The gravitational amplification is measured by comparing the joint distribution in redshift and magnitude of galaxies behind the cluster with that of…

Astrophysics · Physics 2009-10-22 T. J. Broadhurst , A. N. Taylor , J. A. Peacock

Weak lensing by large-scale structure allows a direct measure of the dark matter distribution. We have used parallel images taken with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope to measure weak lensing, or…

We measure the distribution of matter contained within the emptiest regions of the Universe: cosmic voids. We use the large overlap between the Ultraviolet Near-Infrared Optical Northern Survey (UNIONS) and voids identified in the LOWZ and…

We present a simple method for evaluating the nonlinear biasing function of galaxies from a redshift survey. The nonlinear biasing is characterized by the conditional mean of the galaxy density fluctuation given the underlying mass density…

Astrophysics · Physics 2009-10-31 Yair Sigad , Enzo Branchini , Avishai Dekel