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Related papers: Simulation of non-Gaussian CMB maps

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We demonstrate an approach that allows separating two-point correlations created by a Gaussian random field from correlations created by cosmic foregrounds such as polarized dust emission, gravitational lensing and other non-Gaussian…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-26 D. I. Novikov , K. O. Parfenov

We have developed a fast, accurate and generally applicable method for inferring the power spectrum and its uncertainties from maps of the cosmic microwave background (CMB) in the presence of inhomogeneous and correlated noise. For maps…

Astrophysics · Physics 2014-10-13 O. Doré , L. Knox , A. Peel

Light scalars may be ubiquitous in nature, and their quantum fluctuations can produce large non-Gaussianity in the cosmic microwave background temperature anisotropy. The non-Gaussianity may be accompanied with a small admixture of…

Some analyses of recent cosmic microwave background (CMB) data have provided hints that there are deviations from Gaussianity in the WMAP CMB temperature fluctuations. Given the far reaching consequences of such a non-Gaussianity for our…

Astrophysics · Physics 2009-03-31 A. Bernui , M. J. Reboucas

Noncommutative geometry can provide effective description of physics at very short distances taking into account generic effects of quantum gravity. Inflation amplifies tiny quantum fluctuations in the early universe to macroscopic scales…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-18 Tomi S. Koivisto , David F. Mota

The issue of non-Gaussianity is not only related to distinguishing the theories of the origin of primordial fluctuations, but also crucial for the determination of cosmological parameters in the framework of inflation paradigm. We present…

Astrophysics · Physics 2009-11-10 Lung-Yih Chiang , Pavel D. Naselsky

In this paper we will consider the problem of the numerical simulation of non-Gaussian, scalar random fields with a prescribed correlation structure provided either by a theoretical model or computed on a set of observational data.…

Astrophysics · Physics 2009-11-06 Roberto Vio , Paola Andreani , Willem Wamsteker

We present a simple way to calculate non-Gaussianity in inflation using fully non-linear equations on long wavelengths with stochastic sources to take into account the short-wavelength quantum fluctuations. Our formalism includes both…

Astrophysics · Physics 2009-11-10 G. I. Rigopoulos , E. P. S. Shellard , B. J. W. van Tent

A number of experiments for measuring anisotropies of the Cosmic Microwave Background use scanning strategies in which temperature fluctuations are measured along circular scans on the sky. It is possible, from a large number of such…

Astrophysics · Physics 2009-10-30 J. Delabrouille , K. M. Górski , E. Hivon

A new method for estimating the angular power spectrum C_l from cosmic microwave background (CMB) maps is presented, which has the following desirable properties: (1) It is unbeatable in the sense that no other method can measure C_l with…

Astrophysics · Physics 2009-10-07 Max Tegmark

We study the primordial non-Gaussinity predicted from simple models of inflation with a linear potential and superimposed oscillations. This generic form of the potential is predicted by the axion monodromy inflation model, that has…

High Energy Physics - Phenomenology · Physics 2014-11-20 Steen Hannestad , Troels Haugboelle , Philip R. Jarnhus , Martin S. Sloth

We calculate the bispectrum of the gravitational field fluctuations generated during warm inflation, where dissipation of the vacuum potential during inflation is the mechanism for structure formation. The bispectrum is non--zero because of…

Astrophysics · Physics 2011-05-10 S. Gupta , A. Berera , A. F. Heavens , S. Matarrese

Simulating a Gaussian process requires sampling from a high-dimensional Gaussian distribution, which scales cubically with the number of sample locations. Spectral methods address this challenge by exploiting the Fourier representation,…

Machine Learning · Statistics 2026-02-27 Arsalan Jawaid , Abdullah Karatas , Jörg Seewig

We develop a class of nearest-neighbor mixture models that provide direct, computationally efficient, probabilistic modeling for non-Gaussian geospatial data. The class is defined over a directed acyclic graph, which implies conditional…

Methodology · Statistics 2022-06-28 Xiaotian Zheng , Athanasios Kottas , Bruno Sansó

We describe the details of the binned bispectrum estimator as used for the official 2013 and 2015 analyses of the temperature and polarization CMB maps from the ESA Planck satellite. The defining aspect of this estimator is the…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-02 Martin Bucher , Benjamin Racine , Bartjan van Tent

Cosmic Microwave Background (CMB) Anisotropies is a subject of intensive research in several fields of sciences. In this paper we start a systematic development of basic notions and theory in statistics according to the application for CMB.…

Applications · Statistics 2013-12-30 Gyorgy Terdik

We present a model-independent method to test for scale-dependent non-Gaussianities in combination with scaling indices as test statistics. Therefore, surrogate data sets are generated, in which the power spectrum of the original data is…

Astrophysics · Physics 2009-04-05 C. Raeth , G. Morfill , G. Rossmanith , A. J. Banday , K. M. Gorski

We study the large-scale angular correlation signatures of the Cosmic Microwave Background (CMB) temperature fluctuations from WMAP data in several spherical cap regions of the celestial sphere, outside the Kp0 or Kp2 cut-sky masks. We…

Asymmetric beams can create significant bias in estimates of the power spectra from CMB experiments. With the temperature power spectrum many orders of magnitude stronger than the B-mode power spectrum any systematic error that couples the…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-08 Christopher G. R. Wallis , Michael L. Brown , Richard A. Battye , Giampaolo Pisano , Luca Lamagna

We study the topology generated by the temperature fluctuations of the Cosmic Microwave Background (CMB) radiation, as quantified by the number of components and holes, formally given by the Betti numbers, in the growing excursion sets. We…