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Weak gravitational lensing is responsible for the shearing and magnification of the images of high-redshift sources due to the presence of intervening matter. The distortions are due to fluctuations in the gravitational potential, and are…

Astrophysics · Physics 2009-09-29 D. Munshi , P. Valageas , L. Van Waerbeke , A. Heavens

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

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

Primordial non-Gaussianity can lead to a scale-dependent bias in the density of collapsed halos relative to the underlying matter density. The galaxy power spectrum already provides constraints on local-type primordial non-Gaussianity…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-15 Matteo Tellarini , Ashley J. Ross , Gianmassimo Tasinato , David Wands

The lowest multipole moments of the cosmic microwave background (CMB) are smaller than expected for a scale-invariant power spectrum. One possible explanation is a cutoff in the primordial power spectrum below a comoving scale of $k_c…

Astrophysics · Physics 2009-11-10 Michael Kesden , Marc Kamionkowski , Asantha Cooray

Smoothing over structures in general relativity leads to a renormalisation of the background, and potentially many other effects which are poorly understood. Observables such as the distance-redshift relation when averaged on the sky do not…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Chris Clarkson , Obinna Umeh

General relativistic corrections to the galaxy power spectrum appearing at the horizon scale, if neglected, may induce biases on the measured values of the cosmological parameters. In this paper, we study the impact of general relativistic…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 L. Lopez-Honorez , O. Mena , S. Rigolin

The anisotropy of the redshift space bispectrum contains a wealth of cosmological information. This anisotropy depends on the orientation of three vectors ${\bf k_1,k_2,k_3}$ with respect to the line of sight. Here we have decomposed the…

Cosmology and Nongalactic Astrophysics · Physics 2020-02-12 Somnath Bharadwaj , Arindam Mazumdar , Debanjan Sarkar

Cosmological weak lensing gives rise to correlations in the ellipticities of faint galaxies. This cosmic shear signal depends upon the matter power spectrum, thus providing a means to constrain cosmological parameters. It has recently been…

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

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

Weak gravitational lensing by the intervening large-scale structure (LSS) of the Universe is the leading non-linear effect on the anisotropies of the cosmic microwave background (CMB). The integrated line-of-sight mass that causes the…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-26 Alba Kalaja , Giorgio Orlando , Aleksandr Bowkis , Anthony Challinor , P. Daniel Meerburg , Toshiya Namikawa

Local non-Gaussianity, parametrized by $f_{\rm NL}$, introduces a scale-dependent bias that is strongest at large scales, precisely where General Relativistic (GR) effects also become significant. With future data, it should be possible to…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Marco Bruni , Robert Crittenden , Kazuya Koyama , Roy Maartens , Cyril Pitrou , David Wands

The potential of cosmic shear to probe cosmology is well recognized and future optical wide field surveys are currently being designed to optimize the return of cosmic shear science. High precision cosmic shear analysis requires high…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 L. Van Waerbeke

Lensing of the CMB generates a significant bispectrum, which should be detected by the Planck satellite at the 5-sigma level and is potentially a non-negligible source of bias for f_NL estimators of local non-Gaussianity. We extend current…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Antony Lewis , Anthony Challinor , Duncan Hanson

The 21-cm brightness temperature fluctuation from the Dark Ages ($z \simeq 30-100$) will allow us to probe the inflationary epoch on very small scales ($>0.1 \, \mbox{Mpc}^{-1}$), inaccessible to cosmic microwave background experiments.…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-28 Giorgio Orlando , Thomas Flöss , P. Daniel Meerburg , Joseph Silk

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

Since cosmic shear was first observed in 2000, it has become a key cosmological probe and promises to deliver exquisite dark energy constraints. However, shear is inferred from coherent distortions of galaxy shapes, and the relation between…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-19 Enya Van den Abeele , Pierre Astier , Anna Niemiec

Next-generation galaxy surveys will be able to measure perturbations on scales beyond the equality scale. On these ultra-large scales, primordial non-Gaussianity leaves signatures that can shed light on the mechanism by which perturbations…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-10 Mario Ballardini , William Luke Matthewson , Roy Maartens

We present a derivation of the cosmological distance-redshift relation up to second order in perturbation theory. In addition, we find the observed redshift and the lensing magnification to second order. We do not require that the density…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Obinna Umeh , Chris Clarkson , Roy Maartens

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
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