English
Related papers

Related papers: Non-Gaussian Spectra

200 papers

We propose a formalism for estimating the skewness and angular power spectrum of a general Cosmic Microwave Background data set. We use the Edgeworth Expansion to define a non-Gaussian likelihood function that takes into account the…

Astrophysics · Physics 2010-04-30 C. R. Contaldi , P. G. Ferreira , J. Magueijo , K. M. Gorski

Distances in cosmology are usually inferred from observed redshifts - an estimate that is dependent on the local peculiar motion - giving a distorted view of the three dimensional structure and affecting basic observables such as the…

Astrophysics · Physics 2008-12-18 J. Richard Shaw , Antony Lewis

A simple method is presented for the rapid simulation of statistically-isotropic non-Gaussian maps of CMB temperature fluctuations with a given power spectrum and analytically-calculable bispectrum and higher-order polyspectra. The…

Astrophysics · Physics 2009-11-10 Graca Rocha , M. P. Hobson , Sarah Smith , Pedro Ferreira , Anthony Challinor

We present a search for non-Gaussianity in the WMAP first-year data using the two-point correlation function of maxima and minima in the temperature map. We find evidence for non-Gaussianity on large scales, whose origin appears to be…

Astrophysics · Physics 2009-11-13 R. Tojeiro , P. G. Castro , A. F. Heavens , S. Gupta

We study the sample variance of the matter power spectrum for the standard Lambda Cold Dark Matter universe. We use a total of 5000 cosmological N-body simulations to study in detail the distribution of best-fit cosmological parameters and…

In this paper we develop the theory of clusterization of peaks in a Gaussian random field. We have obtained new mathematical results from this theory and the theory of percolation and have proposed a topological method of analysis of sky…

Astrophysics · Physics 2009-10-28 D. I. Novikov , H. E. Jorgensen

The primary science driver for 3D galaxy surveys is their potential to constrain cosmological parameters. Forecasts of these surveys' effectiveness typically assume Gaussian statistics for the underlying matter density, despite the fact…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-27 Andrew Repp , István Szapudi , Julien Carron , Melody Wolk

Using a discrete wavelet based space-scale decomposition (SSD), the spectrum of the skewness and kurtosis is developed to describe the non-Gaussian signatures in cosmologically interesting samples. Because the basis of the discrete wavelet…

Astrophysics · Physics 2007-05-23 Jesus Pando , Li-Zhi Fang

In gravitational wave astronomy, non-Gaussian noise, such as scattered light noise disturbs stable interferometer operation, limiting the interferometer's sensitivity, and reducing the reliability of the analyses. In scattered light noise,…

General Relativity and Quantum Cosmology · Physics 2024-03-20 Shunsei Yamamura , Hirotaka Yuzurihara , Takahiro Yamamoto , Takashi Uchiyama

We computed the power spectrum of weak cosmic shear in models with non-Gaussian primordial density fluctuations. Cosmological initial conditions deviating from Gaussianity have recently attracted much attention in the literature, especially…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 C. Fedeli , L. Moscardini

Non-Gaussian states are essential resources in quantum information processing. In this work, we investigate methods for quantifying bosonic non-Gaussianity in many-body systems. Building on recent theoretical insights into the…

Quantum Physics · Physics 2025-07-15 Kaifeng Bu , Bikun Li

The presence of non--Gaussian features in the Cosmic Microwave Background (CMB) radiation maps represents one of the most long--awaited clues in the search for the actual structure of the primordial radiation, still needing confirmation.…

Astrophysics · Physics 2009-10-22 Alejandro Gangui

Gravitational lensing of the Cosmic Microwave Background (CMB) encodes cosmological information in the observed anisotropies of temperature and polarization. Accurate extraction of this additional information requires precise modeling of…

Cosmology and Nongalactic Astrophysics · Physics 2013-02-07 Aurélien Benoit-Lévy , Kendrick M. Smith , Wayne Hu

We propose a new method for extracting the non-Gaussian signatures on the isotemperature statistics in the cosmic microwave background (CMB) sky, which is induced by the gravitational lensing due to the intervening large-scale structure of…

Astrophysics · Physics 2009-11-06 Masahiro Takada

Recent Cosmic Microwave Background (CMB) observations indicate that the temperature anisotropies arise from quantum fluctuations in the inflationary scenario. In the simplest inflationary models, the distribution of CMB temperature…

Astrophysics · Physics 2009-11-10 J. L. Starck , N. Aghanim , O. Forni

We give new constraints on small-scale non-Gaussianity of primordial curvature perturbations by the use of anisotropies in acoustic reheating. Mixing of local thermal or local kinetic equilibrium systems with different temperatures yields a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Atsushi Naruko , Atsuhisa Ota , Masahide Yamaguchi

This article investigates the non-linear evolution of cosmological perturbations on sub-Hubble scales in order to evaluate the unavoidable deviations from Gaussianity that arise from the non-linear dynamics. It shows that the dominant…

Astrophysics · Physics 2009-02-23 Cyril Pitrou , Jean-Philippe Uzan , Francis Bernardeau

We introduce an exact Bayesian approach to search for non-Gaussianity of local type in Cosmic Microwave Background (CMB) radiation data. Using simulated CMB temperature maps, the newly developed technique is compared against the…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-15 Franz Elsner , Benjamin D. Wandelt

(Abridged) Estimating the uncertainty on the matter power spectrum internally (i.e. directly from the data) is made challenging by the simple fact that galaxy surveys offer at most a few independent samples. In addition, surveys have…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Joachim Harnois-Deraps , Ue-Li Pen

It is possible to classify pixels of a smoothed cosmic microwave background (CMB) fluctuation map according to their local curvature in ``hill'', ``lake'' and ``saddle'' regions. In the Gaussian case, fractional areas occupied by pixels of…

Astrophysics · Physics 2011-05-10 O. Doré , S. Colombi , F. R. Bouchet
‹ Prev 1 3 4 5 6 7 10 Next ›