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We examine general physical parameterisations for viable gravitational models in the $f(R)$ framework. This is related to the mass of an additional scalar field, called the scalaron, that is introduced by the theories. Using a simple…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Shaun A. Thomas , Stephen A. Appleby , Jochen Weller

We study how well the Gaussian approximation is valid for computing the covariance matrices of the convergence power and bispectrum in weak gravitational lensing analyses. We focus on its impact on the cosmological parameter estimations by…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Masanori Sato , Takahiro Nishimichi

When the gravitational lensing of the large-scale structure is calculated from a cosmological model a few assumptions enter: $(i)$ one assumes that the photons follow unperturbed background geodesics, which is usually referred to as the…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-28 Carolina Cuesta-Lazaro , Arnau Quera-Bofarull , Robert Reischke , Bjoern Malte Schaefer

When a luminous source is extended, its distortions by weak gravitational lensing are richer than a mere combination of magnification and shear. In a recent work, we proposed an elegant formalism based on complex analysis to describe and…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-29 Pierre Fleury , Julien Larena , Jean-Philippe Uzan

In this manuscript, we provide a comprehensive study of gravitational lensing by dark compact objects predicted by a Modified Gravity (MOG) based on the Scalar-Vector-Tensor action, and the aim is to analyze new insights into the nature of…

General Relativity and Quantum Cosmology · Physics 2025-03-07 Nagina Rehman , Zoe C. S. Chan , Mubasher Jamil , Mustapha Azreg-Aïnou

We present the results of weak gravitational lensing statistics in four different cosmological $N$-body simulations. The data has been generated using an algorithm for the three-dimensional shear, which makes use of a variable softening…

Astrophysics · Physics 2009-10-31 Andrew J. Barber , Peter A. Thomas , H. M. P. Couchman , C. J. Fluke

Weak gravitational lensing has several important effects on the cosmic microwave background (CMB): it changes the CMB power spectra, induces non-Gaussianities, and generates a B-mode polarization signal that is an important source of…

Astrophysics · Physics 2007-05-23 Antony Lewis , Anthony Challinor

Context. Weak gravitational lensing is a powerful probe of large-scale structure and cosmology. Most commonly, second-order correlations of observed galaxy ellipticities are expressed as a projection of the matter power spectrum,…

Cosmology and Nongalactic Astrophysics · Physics 2010-08-25 Martin Kilbinger

We study the amplitude of the weak gravitational lensing signal as a function of stellar mass around a sample of relatively isolated galaxies. This selection of lenses simplifies the interpretation of the observations, which consist of data…

Astrophysics · Physics 2009-11-13 Lanlan Tian , Henk Hoekstra , Hongsheng Zhao

We investigate the information content of various cosmic shear statistics on the theory of gravity. Focusing on the Hu-Sawicki-type $f(R)$ model, we perform a set of ray-tracing simulations and measure the convergence bispectrum, peak…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-25 Masato Shirasaki , Takahiro Nishimichi , Baojiu Li , Yuichi Higuchi

Dark matter currents in the large-scale structure give rise to gravitomagnetic terms in the metric, which affect the light propagation. Corrections to the weak lensing power spectrum due to these gravitomagnetic potentials are evaluated by…

Astrophysics · Physics 2013-03-07 Bjoern Malte Schaefer , Matthias Bartelmann

Estimators for weak lensing observables such as shear and convergence generally have non-linear corrections, which, in principle, make weak lensing power spectra sensitive to primordial non-Gaussianity. In this paper, we quantitatively…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 Donghui Jeong , Fabian Schmidt , Emiliano Sefusatti

We perform a principal component analysis to assess ability of future observations to measure departures from General Relativity in predictions of the Poisson and anisotropy equations on linear scales. In particular, we focus on how the…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-22 Shinsuke Asaba , Chiaki Hikage , Kazuya Koyama , Gong-Bo Zhao , Alireza Hojjati , Levon Pogosian

Matter near a gravitational lens galaxy or projected along the line of sight (LOS) can affect strong lensing observables by more than contemporary measurement errors. We simulate lens fields with realistic three-dimensional mass…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-12 Curtis McCully , Charles R. Keeton , Kenneth C. Wong , Ann I. Zabludoff

Observations of the large-scale structure (LSS) implicitly assume an ideal FLRW observer with the ambient structure having no influence on the observer. However, due to correlations in the LSS, cosmological observables are dependent on the…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-05 Robert Reischke , Björn malte Schäfer , Krzysztof Bolejko , Geraint F. Lewis , Max Lautsch

The wealth of incoming and future cosmological observations will allow us to map out the structure and evolution of the observable universe to an unprecedented level of precision. Among these observations is the weak gravitational lensing…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 M. A. Troxel , Mustapha Ishak

Weak gravitational lensing observations are a key science driver for the NASA Wide Field Infrared Survey Telescope (WFIRST). To validate the performance of the WFIRST infrared detectors, we have performed a laboratory emulation of weak…

Instrumentation and Methods for Astrophysics · Physics 2015-06-16 Suresh Seshadri , Charles Shapiro , Timothy Goodsall , Jason Fucik , Christopher M. Hirata , Jason Rhodes , Barnaby Rowe , Roger Smith

Weak gravitational lensing of background galaxies by intervening matter directly probes the mass distribution in the universe. This distribution, and its evolution at late times, is sensitive to both the dark energy, a negative pressure…

Astrophysics · Physics 2009-11-07 Kevork Abazajian , Scott Dodelson

We present a survey of the cosmological applications of the next generation of weak lensing surveys, paying special attention to the computational challenges presented by the number of galaxies, $N_{gal} ~$ 10$^{5}$. We focus on optimal…

Astrophysics · Physics 2009-11-07 N. Padmanabhan , U. Seljak , U. L. Pen

Several recent studies show that bright, intermediate and high redshift optically and radio selected QSOs are positively correlated with nearby galaxies on a range of angular scales up to a degree. Obscuration by unevenly distributed…

Astrophysics · Physics 2009-10-31 Liliya L. R. Williams