English
Related papers

Related papers: Analysis of non-Gaussian CMB maps based on the N-p…

200 papers

Using the 5 year WMAP data, we re-investigate claims of non-Gaussianities and asymmetries detected in local curvature statistics of the 1 year WMAP data. In Hansen et al 2004, it was found that the northern ecliptic hemisphere was…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Øystein Rudjord , Nicolaas E. Groeneboom , Frode K. Hansen , Paolo Cabella

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

Non-Gaussian distributions of cosmic microwave background (CMB) anisotropies have been proposed to reconcile the discrepancies between different experiments at half-degree scales (Coulson et al. 1994). Each experiment probes a different…

Astrophysics · Physics 2009-10-22 Xiaochun Luo

[Abridged] In recent works we have proposed two new large-angle non-Gaussianity indicators based on skewness and kurtosis of patches of CMB sky-sphere, and used them to find out significant deviation from Gaussianity in frequency bands and…

Cosmology and Nongalactic Astrophysics · Physics 2012-02-15 A. Bernui , M. J. Reboucas

We search the high-latitude portion of the COBE Differential Microwave Radiometers (DMR) 4-year sky maps for evidence of a non-Gaussian temperature distribution in the cosmic microwave background. The genus, 3-point correlation function,…

Astrophysics · Physics 2009-10-28 A. Kogut , A. J. Banday , C. L. Bennett , K. Gorski , G. Hinshaw , G. F. Smoot , E. L. Wright

We test the consistency of estimates of the non-linear coupling constant f_{NL} using non-Gaussian CMB maps generated by the method described in (Liguori, Matarrese and Moscardini 2003). This procedure to obtain non-Gaussian maps differs…

Astrophysics · Physics 2009-11-10 P. Cabella , M. Liguori , F. K. Hansen , D. Marinucci , S. Matarrese , L. Moscardini , N. Vittorio

We perform multi-scale non-Gaussianity detection and localization to the Wilkinson Microwave Anisotropy Probe (WMAP) first-year data in both wavelet and real spaces. Such an analysis is facilitated by spherical wavelet transform and inverse…

Astrophysics · Physics 2009-11-11 Xin Liu , Shuang Nan Zhang

We present a careful frequentist analysis of one- and two-point statistics of the hot and cold spots in the cosmic microwave background (CMB) data obtained by the Wilkinson Microwave Anisotropy Probe (WMAP). Our main result is the detection…

Astrophysics · Physics 2007-05-23 David L. Larson , Benjamin D. Wandelt

Local scaling properties of the co-added foreground-cleaned three-year Wilkinson Microwave Anisotropy Probe (WMAP) data are estimated using weighted scaling indices. The scaling index method (SIM) is - for the first time - adapted and…

Astrophysics · Physics 2009-05-21 C. Raeth , P. Schuecker , A. J. Banday

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 describe an algorithm to generate temperature and polarization maps of the cosmic microwave background radiation containing non-Gaussianity of arbitrary local type. We apply an optimized quadrature scheme that allows us to predict and…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-04 Franz Elsner , Benjamin D. Wandelt

We look for a non-Gaussian signal in the WMAP 5-year temperature anisotropy maps by performing a needlet-based data analysis. We use the foreground-reduced maps obtained by the WMAP team through the optimal combination of the W, V and Q…

We investigate the use of wavelet transforms in detecting and characterising non-Gaussian structure in maps of the cosmic microwave background (CMB). We apply the method to simulated maps of the Kaiser-Stebbins effect due to cosmic strings…

Astrophysics · Physics 2009-10-31 MP Hobson , AW Jones , AN Lasenby

We propose a fast and efficient bispectrum statistic for Cosmic Microwave Background (CMB) temperature anisotropies to constrain the amplitude of the primordial non-Gaussian signal measured in terms of the non-linear coupling parameter…

Astrophysics · Physics 2009-11-11 P. Cabella , F. K. Hansen , M. Liguori , D. Marinucci , S. Matarrese , L. Moscardini , N. Vittorio

The extraction of cosmological parameters from microwave background observations relies on specific assumptions about the statistical properties of the data, in particular that the p-point distributions of temperature fluctuations are…

Astrophysics · Physics 2007-05-23 Patrick Dineen , Peter Coles

Recent measurements of the temperature fluctuations of the cosmic microwave background (CMB) radiation from the WMAP satellite provide indication of a non-Gaussian behavior. Although the observed feature is small, it is detectable and…

Astrophysics · Physics 2008-11-26 Armando Bernui , Constantino Tsallis , Thyrso Villela

The skew-spectrum statistic introduced by Munshi & Heavens (2010) has recently been used in studies of non-Gaussianity from diverse cosmological data sets including the detection of primary and secondary non-Gaussianity of Cosmic Microwave…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Donough Regan , Dipak Munshi

We extend the previously described CMB Gibbs sampling framework to allow for exact Bayesian analysis of anisotropic universe models, and apply this method to the 5-year WMAP temperature observations. This involves adding support for…

Astrophysics · Physics 2011-02-11 Nicolaas E. Groeneboom , Hans Kristian Eriksen

We present a Gaussianity analysis of the WMAP 5-year Cosmic Microwave Background (CMB) temperature anisotropy data maps. We use several third order estimators based on the spherical Mexican hat wavelet. We impose constraints on the local…

In the recent years, non-Gaussianity and statistical isotropy of the Cosmic Microwave Background (CMB) was investigated with various statistical measures, first and foremost by means of the measurements of the WMAP satellite. In this…

Cosmology and Nongalactic Astrophysics · Physics 2011-10-21 G. Rossmanith , H. Modest , C. Raeth , A. J. Banday , K. M. Gorski , G. Morfill