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We repeat the directional spherical real Morlet wavelet analysis used to detect non-Gaussianity in the WMAP 1-year data (McEwen et al. 2005a), on the WMAP 3-year data. The non-Gaussian signal previously detected is indeed present in the…

Astrophysics · Physics 2011-02-11 J. D. McEwen , M. P. Hobson , A. N. Lasenby , D. J. Mortlock

A considerable effort has recently gone into the study of Gaussianity of cosmic microwave background (CMB) data. Among such attempts, there is one with two non-Gaussianity indicators, proposed by the authors, and used in a search for…

Cosmology and Nongalactic Astrophysics · Physics 2009-07-10 A. Bernui , M. J. Reboucas

This paper explores a novel application of spherical convolutional neural networks (CNNs) to detect primordial non-Gaussianity in the cosmic microwave background (CMB), a key probe of inflationary dynamics. While effective, traditional…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-28 Jorik Melsen , Thomas Flöss , P. Daniel Meerburg

Recent second-order perturbation computations have provided an accurate prediction for the primordial gravitational potential $\Phi(x)$ in scenarios in which cosmological perturbations are generated either during or after inflation. This…

Astrophysics · Physics 2008-11-26 M. Liguori , F. K. Hansen , E. Komatsu , S. Matarrese , A. Riotto

We investigate the relative sensitivities of several tests for deviations from Gaussianity in the primordial distribution of density perturbations. We consider models for non-Gaussianity that mimic that which comes from inflation as well as…

Astrophysics · Physics 2009-10-31 Licia Verde , Raul Jimenez , Marc Kamionkowski , Sabino Matarrese

We use Minkowski Functionals to explore the presence of non-Gaussian signatures in simulated cosmic microwave background (CMB) maps. Precisely, we analyse the non-Gaussianities produced from the angular power spectra emerging from a class…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-08 Camila P. Novaes , Micol Benetti , Armando Bernui

Primordial non-Gaussianity is a sensitive probe of the inflationary era, with a number of important theoretical targets living an order of magnitude beyond the reach of current CMB constraints. Maps of the large-scale structure of the…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-07 Daniel Baumann , Daniel Green

In (Hansen et al. 2002) we presented a new approach for measuring non-Gaussianity of the Cosmic Microwave Background (CMB) anisotropy pattern, based on the multivariate empirical distribution function of the spherical harmonics a_lm of a…

Astrophysics · Physics 2010-11-19 Frode K. Hansen , Domenico Marinucci , Nicola Vittorio

We introduce a new mathematical tool (a direction-dependent probe) to analyse the randomness of purported isotropic Gaussian random fields on the sphere. We apply the probe to assess the full-sky cosmic microwave background (CMB)…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-29 J. Hamann , Q. T. Le Gia , I. H. Sloan , Y. G. Wang , R. S. Womersley

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 present results from a first test of the Gaussianity of degree-scale cosmic microwave background (CMB) anisotropy. We investigate Gaussianity of the CMB anisotropy by studying the topology of CMB anisotropy maps from the QMAP and…

Astrophysics · Physics 2009-10-07 Chan-Gyung Park , Changbom Park , Bharat Ratra , Max Tegmark

We present new constraints on the local-type primordial non-Gaussianity parameter, $f_\mathrm{NL}^\mathrm{local}$, through analysis of the scale-dependent bias effect on the cosmic infrared background (CIB). To avoid biases from galactic…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-06 Joseph Thornton , Fiona McCarthy , Carmen Embil Villagra , Blake D. Sherwin

Analyses of recent cosmic microwave background (CMB) observations have provided increasing indications for the existence of large scale anisotropy in the universe. Given the far reaching consequences of such an anisotropy for our…

Astrophysics · Physics 2009-09-29 A. Bernui , B. Mota , M. J. Reboucas , R. Tavakol

We investigate the local properties of WMAP Cold Spot (CS) by defining the local statistics: mean temperature, variance, skewness and kurtosis. We find that, compared with the \emph{coldest spots} in random Gaussian simulations, WMAP CS…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-30 Wen Zhao

The primordial non-Gaussianity parameters fNL and tauNL may be scale-dependent. We investigate the capability of future measurements of the CMB mu-distortion, which is very sensitive to small scales, and of the large-scale halo bias to test…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-27 Matteo Biagetti , Hideki Perrier , Antonio Riotto , Vincent Desjacques

We present a novel approach to estimate the value of primordial non-Gaussianity ($f_{\rm NL}$) parameter directly from the Cosmic Microwave Background (CMB) maps using a convolutional neural network (CNN). While traditional methods rely on…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-26 Chandan G. Nagarajappa , Yin-Zhe Ma

We present an analysis of the Minkowski Functionals (MFs) describing the WMAP three-year temperature maps to place limits on possible levels of primordial non-Gaussianity. In particular, we apply perturbative formulae for the MFs to give…

We introduce and study the distribution of an estimator for the normalized bispectrum of the Cosmic Microwave Background (CMB) anisotropy. We use it to construct a goodness of fit statistic to test the coadded 53 and 90 GHz COBE-DMR 4 year…

Astrophysics · Physics 2009-10-30 Pedro G. Ferreira , Joao Magueijo , Krzysztof M. Górski

We investigate optimization strategies to measure primordial non-Gaussianity with future spectroscopic surveys. We forecast measurements coming from the 3D galaxy power spectrum and compute constraints on primordial non-Gaussianity…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-26 Alvise Raccanelli , Olivier Dore , Neal Dalal
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