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Related papers: Needlet Bispectrum Asymmetries in the WMAP 5-year …

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We apply the Gabor transform methodology proposed in (Hansen et al. 2002, 2003) to the WMAP data in order to test the statistical properties of the CMB fluctuation field and specifically to evaluate the fundamental assumption of…

Astrophysics · Physics 2009-05-29 F. K. Hansen , A. J. Banday , K. M. Gorski

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

We cross-correlate the cosmic microwave background temperature anisotropy maps from the WMAP, MAXIMA-I, and MAXIMA-II experiments. We use the cross-spectrum, which is the spherical harmonic transform of the angular two-point correlation…

In recent years the goal of estimating different cosmological parameters precisely has set new challenges in the effort to accurately measure the angular power spectrum of CMB. This has required removal of foreground contamination as well…

Astrophysics · Physics 2008-11-26 Rajib Saha , Simon Prunet , Pankaj Jain , Tarun Souradeep

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

Many inflation models predict that primordial density perturbations have a nonzero three-point correlation function, or bispectrum in Fourier space. Of the several possibilities for this bispectrum, the most commmon is the local-model…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-01 Razieh Emami , Emanuela Dimastrogiovanni , Jens Chluba , Marc Kamionkowski

We have independently measured the genus topology of the temperature fluctuations in the cosmic microwave background seen in the Wilkinson Microwave Anisotropy Probe (WMAP) 3-year data. A genus analysis of the WMAP data indicates…

We analyze the 3-year WMAP data and look for a deviation from Gaussianity in the form of a 3-point function that has either of the two theoretically motivated shapes: local and equilateral. There is no evidence of departure from Gaussianity…

Astrophysics · Physics 2009-11-11 Paolo Creminelli , Leonardo Senatore , Matias Zaldarriaga , Max Tegmark

We have used the seven year Wilkinson Microwave Anisotropy Probe (WMAP) data in order to update the measurements of the intensity signal in the G159.6-18.5 region within the Perseus Molecular Complex, and to set constraints on the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 C. H. Lopez-Caraballo , J. A. Rubino-Martin , R. Rebolo , R. Genova-Santos

We present a framework to compute non-Gaussian likelihoods for two-point correlation functions. The non-Gaussianity is most pronounced on large scales that will be well-measured by stage-IV weak-lensing surveys. We show how such a…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-09 Veronika Oehl , Tilman Tröster

Using a set of multifrequency cross spectra computed from the 3 year WMAP sky maps, we fit for the unresolved point-source contribution. For a white-noise power spectrum, we find a Q-band amplitude of A=0.011 +/- 0.001 muK^2 sr (antenna…

Astrophysics · Physics 2011-02-11 K. M. Huffenberger , H. K. Eriksen , F. K. Hansen

Spatially referenced data often have autocovariance functions with elliptical isolevel contours, a property known as geometric anisotropy. The anisotropy parameters include the tilt of the ellipse (orientation angle) with respect to a…

Statistics Theory · Mathematics 2021-10-04 Manolis P. Petrakis , Dionissios T. Hristopulos

This paper reviews the application of a novel methodology for analysing the isotropy of the universe by probing the alignment of local structures in the CMB. The strength of the proposed methodology relies on the steerable wavelet filtering…

Astrophysics · Physics 2009-11-11 P. Vielva , Y. Wiaux , E. Martinez-Gonzalez , P. Vandergheynst

Noticeable deviations from the prediction of the fiducial LCDM cosmology are found in the angular power spectrum of the CMB. Besides large-angle anomalies, the WMAP 1st year data revealed a dip in the power spectrum at l \sim 200, which…

Cosmology and Nongalactic Astrophysics · Physics 2011-05-12 Amanda Yoho , Francesc Ferrer , Glenn D. Starkman

We present a model-independent investigation of the WMAP data with respect to scale- dependent non-Gaussianities (NGs) by employing the method of constrained randomization. For generating so-called surrogate maps a shuffling scheme is…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 C. Raeth , A. J. Banday , G. Rossmanith , H. Modest , R. Suetterlin , K. M. Gorski , J. Delabrouille , G. E. Morfill

We probe the anisotropy of the large-scale structure (LSS) with the WISE-2MASS catalogue. This analysis is performed by a directional comparison of the galaxy number counts through the entire celestial sphere once systematic effects, such…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-23 C. A. P. Bengaly , A. Bernui , J. S. Alcaniz , H. S. Xavier , C. P. Novaes

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

Measurements of the two-point angular correlation function w(\theta) for 407 short gamma-ray bursts collected in the Current BATSE Catalogue reveal a ~2 \sigma deviation from isotropy on angular scales \theta ~ 2-4 degrees. Such an…

Astrophysics · Physics 2009-11-07 M. Magliocchetti , G. Ghirlanda , A. Celotti

We studied the WMAP temperature anisotropy data using two different methods. The derived signal gradient maps show regions with low mean gradients in structures near the ecliptic poles and higher gradient values in the wide ecliptic…

Astrophysics · Physics 2007-05-23 K. T. Chyzy , B. Novosyadlyj , M. Ostrowski

We investigate invariant random fields on the sphere using a new type of spherical wavelets, called needlets. These are compactly supported in frequency and enjoy excellent localization properties in real space, with quasi-exponentially…

Statistics Theory · Mathematics 2009-09-29 P. Baldi , G. Kerkyacharian , D. Marinucci , D. Picard