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Related papers: Gaussianity

200 papers

We use simulated maps of the cosmic microwave background anisotropy to quantify the ability of different statistical tests to discriminate between Gaussian and non-Gaussian models. Despite the central limit theorem on large angular scales,…

Astrophysics · Physics 2009-10-31 Nicholas G. Phillips , A. Kogut

In this paper we propose a new statistic capable of detecting non-Gaussianity in the CMB. The statistic is defined in Fourier space, and therefore naturally separates angular scales. It consists of taking another Fourier transform, in…

Astrophysics · Physics 2010-04-08 Alex Lewin , Andreas Albrecht , Joao Magueijo

The current status of the recent developments of the second-order gauge-invariant cosmological perturbation theory is reviewed. To show the essence of this perturbation theory, we concentrate only on the universe filled with a single scalar…

General Relativity and Quantum Cosmology · Physics 2016-08-24 Kouji Nakamura

Inflationary cosmologies predict Gaussian primordial fluctuations, but subsequent gravitational lensing of the CMB disturbs its Gaussianity. Knowledge of the specific signature of lensing is necessary to distinguish a lensed Gaussian sky…

Astrophysics · Physics 2007-05-23 Serge Winitzki

There was a question raised at this meeting as to the best way to present the results of experiments measuring anisotropies in the CMB. Here we will make some simple comments about the 3 main competing methods and some suggestions. In…

Astrophysics · Physics 2007-05-23 Martin White , Douglas Scott

We propose a rigorous, non-perturbative, Bayesian framework which enables one jointly to test Gaussianity and estimate the power spectrum of CMB anisotropies. It makes use of the Hilbert space of an harmonic oscillator to set up an exact…

Astrophysics · Physics 2009-10-31 Graca Rocha , Joao Magueijo , Mike Hobson , Anthony Lasenby

We discuss the tests of nonGaussianity in CMB maps using morphological statistics known as Minkowski functionals. As an example we test degree-scale cosmic microwave background (CMB) anisotropy for Gaussianity by studying the \qmask map…

Astrophysics · Physics 2007-05-23 Sergei F. Shandarin , Hume A. Feldman , Yongzhong Xu , Max Tegmark

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

A compact overview of the status of CMB anisotropy results and their cosmological interpretation. Section headings: Introduction; CMB Spectrum; Description of CMB Anisotropies; Cosmological Parameters; Physics of Anisotropies; Current…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-09 Douglas Scott , George F. Smoot

We develop the formalism necessary to study four-point functions of the cosmic microwave background (CMB) temperature and polarization fields. We determine the general form of CMB trispectra, with the constraints imposed by the assumption…

Astrophysics · Physics 2011-05-12 Takemi Okamoto , Wayne Hu

Observed CMB anisotropies are lensed, and the lensed power spectra can be calculated accurately assuming the lensing deflections are Gaussian. However, the lensing deflections are actually slightly non-Gaussian due to both non-linear…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-12 Antony Lewis , Geraint Pratten

We consider corrections to the underlying cosmology due to secondary contributions from weak gravitational lensing, the integrated Sachs-Wolfe effect, and the Sunyaev-Zel'dovich effect contained in the trispectrum. We incorporate these…

Cosmology and Nongalactic Astrophysics · Physics 2010-12-17 Joseph Smidt , Shahab Joudaki , Paolo Serra , Alexandre Amblard , Asantha Cooray

This review presents, in a self-consistent manner, those analytical tools that are relevant for the analysis of the physics of CMB anisotropies generated in different theoretical models of the early Universe. After introducing the physical…

Astrophysics · Physics 2009-11-10 Massimo Giovannini

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 discuss three recent developments in the calculation of CMB anisotropies. First, we consider relativistic corrections to the Sunyaev-Zel'dovich effect. By extending the Kompaneets equation to the relativistic domain we are able to derive…

Astrophysics · Physics 2009-09-25 A. D. Challinor , A. N. Lasenby

A compact overview of the status of CMB anisotropy results and their cosmological interpretation up until the end of 2005. Sections headings: Introduction; Description of CMB Anisotropies; Cosmological Parameters; Physics of Anisotropies;…

Astrophysics · Physics 2007-05-23 Douglas Scott , George Smoot

We provide an analytical approach to the second-order Cosmic Microwave Background (CMB) anisotropies generated by the non-linear dynamics taking place at last scattering. We study the acoustic oscillations of the photon-baryon fluid in the…

Astrophysics · Physics 2010-10-27 Nicola Bartolo , Sabino Matarrese , Antonio Riotto

We investigate the power of geometrical estimators on detecting non-Gaussianity in the cosmic microwave background. In particular the number, eccentricity and Gaussian curvature of excursion sets above (and below) a threshold are studied.…

Astrophysics · Physics 2011-05-10 R. B. Barreiro , E. Martinez-Gonzalez , J. L. Sanz

In this paper we present a complete computation of the Cosmic Microwave Background (CMB) anisotropies up to third order from gravitational perturbations accounting for scalar, vector and tensor perturbations. We then specify our results to…

Astrophysics · Physics 2008-11-26 G. D'Amico , N. Bartolo , S. Matarrese , A. Riotto

This is the obligatory Cosmic Microwave Background review. I discuss the current status of CMB anisotropies, together with some points on the related topic of the Far-Infrared Background. We have already learned a number of important things…

Astrophysics · Physics 2007-05-23 Douglas Scott