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Likelihood fitting to two-point clustering statistics made from galaxy surveys usually assumes a multivariate normal distribution for the measurements, with justification based on the central limit theorem given the large number of…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-23 Mike Shengbo Wang , Will J. Percival , Santiago Avila , Robert Crittenden , Davide Bianchi

(Abridged) By comparing the frequency of typical events with that of unusual events, one can test whether the cosmological density distribution function is consistent with the normally made assumption of Gaussianity. To this end, we compare…

Astrophysics · Physics 2009-10-30 Weihsueh A. Chiu , Jeremiah P. Ostriker , Michael A. Strauss

We consider the expected level of primordial non-Gaussianities in models in which density perturbations are produced by spatial fluctuations in the decay rate of the inflaton. We consider both the non-Gaussianities resulting from the…

Astrophysics · Physics 2008-11-26 Matias Zaldarriaga

In the standard model for structure formation, bound objects originate from the gravitational collapse of small perturbations arising from quantum fluctuations with random phases. In other scenarios, based on defects, structures are seeded…

Astrophysics · Physics 2009-11-06 Licia Verde , Alan F. Heavens

Cosmic microwave background observations are most commonly analyzed by estimating the power spectrum. In the limit where the CMB statistics are perfectly Gaussian, this extracts all the information, but the CMB also contains detectable…

Cosmology and Nongalactic Astrophysics · Physics 2011-11-09 Kendrick M. Smith

A description of CMB temperature fluctuations beyond the power spectrum is important for verifying models of structure formation, especially in view of forthcoming high-resolution observations. We argue that higher-order statistics of…

Astrophysics · Physics 2007-05-23 S. Winitzki , J. H. P. Wu

We study the fluctuations in the vacuum zero point energy associated to quantum fields and their statistical distributions during inflation. It is shown that the perturbations in the vacuum zero point energy have large amplitudes which are…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-20 Hassan Firouzjahi

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

This document describes analytical and numerical techniques for the generation of Gaussian density fields, which represent cosmological density perturbations. The mathematical techniques involved in the generation of density harmonics in…

Astrophysics · Physics 2007-05-23 Hugo Martel

Primordial non-Gaussianity is a potentially powerful discriminant of the physical mechanisms that generated the cosmological fluctuations observed today. Any detection of non-Gaussianity would have profound implications for our…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Vincent Desjacques , Uros Seljak

We calculate the higher order moments in a sequence of models where the initial density fluctuations are drawn from a chi^2_nu distribution with a power-law power spectrum. For large values of nu the distribution is approximately gaussian,…

Astrophysics · Physics 2009-10-31 Martin White

The late-time effect of primordial non-Gaussianity offers a window into the physics of inflation and the very early Universe. In this work we study the consequences of a particular class of primordial non-Gaussianity that is fully…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-09 G. A. Peña , G. N. Candlish

An attractive and simple hypothesis for the formation of large-scale structure is that it developed by gravitational instability from primordial fluctuations with an initially Gaussian probability distribution. Non-linear gravitational…

Astrophysics · Physics 2015-06-24 Ewa Luiza Lokas , Roman Juszkiewicz , David Weinberg , Francois Bouchet

The primordial non-Gaussianity signal, if measured accurately, will allow us to distinguish between different candidate models for the cosmic inflation. Since the galaxy groups located in void regions are rare events, their abundance may be…

Astrophysics · Physics 2009-12-15 Hyunmi Song , Jounghun Lee

The proper general relativistic description of the observed galaxy power spectrum is substantially different from the standard Newtonian description on large scales, providing a unique opportunity to test general relativity on horizon…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-17 Jaiyul Yoo , Nico Hamaus , Uros Seljak , Matias Zaldarriaga

A major goal of cosmology is to understand the nature of the field(s) which drove primordial Inflation. Through future observations, the statistics of large-scale structure will allow us to probe primordial non-Gaussianity of the curvature…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-14 Dionysios Karagiannis , Roy Maartens , Shun Saito , José Fonseca , Stefano Camera , Chris Clarkson

Here we review the present status of modelling of and searching for primordial non-Gaussianity of cosmological perturbations. After introducing the models for non-Gaussianity generation during inflation, we discuss the search for…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-21 Marco Celoria , Sabino Matarrese

New Ekpyrotic Cosmology is an alternative scenario of the early universe which relies on a phase of slow contraction before the big bang. We calculate the 3-point and 4-point correlation functions of primordial density perturbations and…

High Energy Physics - Theory · Physics 2008-11-26 Evgeny I. Buchbinder , Justin Khoury , Burt A. Ovrut

We use the formalism of constrained Gaussian random field to compute a precise large scale simulation of the 60 Mpc/h volume of our Local Universe. We derive the constraints from the reconstructed peculiar velocities of the 2MASS Redshift…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Guilhem Lavaux
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