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Context. The overdensity inside a cosmological sub-volume and the tidal fields from its surroundings affect the matter distribution of the region. The resulting difference between the local and global power spectra is characterized by the…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-11 Gábor Rácz , István Szapudi , István Csabai

Forthcoming cosmic shear surveys will make precise measurements of the matter density field down to very small scales, scales which are dominated by baryon feedback. The modelling of baryon feedback is crucial to ensure unbiased…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-10 Alessandro Maraio , Alex Hall , Andy Taylor

A phenomenological power spectrum of primordial density perturbations has been constructed by using both COBE data to probe the large wavelength region, and a double power law, locally deduced from galaxy catalogs, which describes the…

Astrophysics · Physics 2008-02-03 S. Torres , R. Fabbri , R. Ruffini

On large scales, the higher order moments of the mass distribution, $S_J=\xibar_J/\xibar_2^{J-1}$, e.g., the skewness $S_3$ and kurtosis $S_4$, can be predicted using non-linear perturbation theory. Comparison of these predictions with…

Astrophysics · Physics 2009-10-22 E. Gaztanaga , J. Frieman

With the availability of galaxy distance indicators in weak lensing surveys, lensing tomography can be harnessed to constrain the three-dimensional (3D) matter power spectrum over a range of redshift and physical scale. By combining…

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

The Covariant Spectator Theory (CST) is used to calculate the mass spectrum and vertex functions of heavy-light and heavy mesons in Minkowski space. The covariant kernel contains Lorentz scalar, pseudoscalar, and vector contributions. The…

High Energy Physics - Phenomenology · Physics 2017-01-04 Sofia Leitão , Alfred Stadler , M. T. Peña , Elmar P. Biernat

We compute the cosmic microwave background temperature bispectrum generated by nonlinearities at recombination on all scales. We use CosmoLib$2^{\rm nd}$, a numerical Boltzmann code at second-order to compute CMB bispectra on the full sky.…

Cosmology and Nongalactic Astrophysics · Physics 2015-04-08 Zhiqi Huang , Filippo Vernizzi

We compute the effects induced by the use of small CMB maps on the measurement of the $\cl{l}$ coefficients of the angular power spectrum and show that small systematic effects have to be taken into account. We also compute numerically the…

Astrophysics · Physics 2007-08-06 C. Magneville , J. P. Pansart

We discuss the non-Gaussian contribution to the power spectrum covariance of cosmic microwave background (CMB) anisotropies resulting through weak gravitational lensing angular deflections and the correlation of deflections with secondary…

Astrophysics · Physics 2009-11-07 Asantha Cooray

To probe cosmological fields beyond the Gaussian level, three-point statistics can be used, all of which are related to the bispectrum. Hence, measurements of CMB anisotropies, galaxy clustering, and weak gravitational lensing alike have to…

Cosmology and Nongalactic Astrophysics · Physics 2010-02-03 B. Joachimi , X. Shi , P. Schneider

We report the experimental demonstration of coherent control with high power, broadband squeezed vacuum. Although incoherent and exhibiting the statistics of a thermal noise, broadband squeezed vacuum is shown to induce certain two-photon…

Quantum Physics · Physics 2011-12-06 Barak Dayan , Avi Pe'er , Asher A. Friesem , Yaron Silberberg

Weak gravitational lensing observations probe the spectrum and evolution of density fluctuations and the cosmological parameters which govern them. At low redshifts, the non-linear gravitational evolution of large scale structure produces a…

Astrophysics · Physics 2009-10-31 Asantha Cooray , Wayne Hu

Quadratic methods with heuristic weighting (e.g. pseudo-C_l or correlation function methods) represent an efficient way to estimate power spectra of the cosmic microwave background (CMB) anisotropies and their polarization. We construct the…

Astrophysics · Physics 2008-11-26 Anthony Challinor , Gayoung Chon

We analyse the covariance of the one-dimensional mass power spectrum along lines of sight. The covariance reveals the correlation between different modes of fluctuations in the cosmic density field and gives the sample variance error for…

Astrophysics · Physics 2009-11-10 Hu Zhan , Daniel Eisenstein

Super sample covariance (SSC) is important when estimating covariance matrices using a set of mock catalogues for galaxy surveys. If the underlying cosmological simulations do not include the variation in background parameters appropriate…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-05 Greg Schreiner , Alex Krolewski , Shahab Joudaki , Will J. Percival

We investigate influences of the curved field-space metric of multi-field inflationary models on the squeezed bispectrum. The reduced bispectrum in squeezed limit is computed using the {\delta}N formalism. The calculation is performed under…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-05 Sakdithut Jitpienka , Khamphee Karwan

A new method to determine the bias parameter of galaxies relative to matter is suggested. The method is based on the assumption that gravity is the dominating force which determines the formation of the structure in the Universe. Due to…

Astrophysics · Physics 2009-10-31 J. Einasto , M. Einasto , E. Tago , V. M"uller , A. Knebe , R. Cen , A. A. Starobinsky , F. Atrio-Barandela

The forthcoming generation of wide-field galaxy surveys will probe larger volumes and galaxy densities, thus allowing for a much larger signal-to-noise ratio for higher-order clustering statistics, in particular the galaxy bispectrum.…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-15 Azadeh Moradinezhad Dizgah , Hayden Lee , Marcel Schmittfull , Cora Dvorkin

Recent studies have demonstrated that {\em secondary} non-Gaussianity induced by gravity will be detected with a high signal-to-noise (S/N) by future and even by on-going weak lensing surveys. One way to characterise such non-Gaussianity is…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-05 D. Munshi , T. Namikawa , T. D. Kitching , J. D. McEwen , R. Takahashi , F. R. Bouchet , A. Taruya , B. Bose
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