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Related papers: Testing the Gaussianity of the COBE-DMR data with …

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Using an analytical model for the Cosmic Microwave Background anisotropies produced by textures, we compute the resulting collapsed three--point correlation function and the {\it rms} expected value due to the cosmic variance. We apply our…

Astrophysics · Physics 2009-10-28 Alejandro Gangui , Silvia Mollerach

The COBE satellite has provided the only comprehensive multi-frequency full-sky observations of the microwave sky available today. Assessment of the observations requires a detailed likelihood analysis to extract the maximum amount of…

Astrophysics · Physics 2007-05-23 K. M. Gorski

Weak gravitational lensing analyses are fundamentally limited by the intrinsic, non-Gaussian distribution of galaxy shapes. We explore alternative statistics for samples of ellipticity measurements that are unbiased, efficient, and robust.…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-31 Merijn Smit , Konrad Kuijken

The first two years of COBE DMR observations of the CMB anisotropy are analyzed and compared with our previously published first year results. The results are consistent, but the addition of the second year of data increases the precision…

When nonlinear measures are estimated from sampled temporal signals with finite-length, a radius parameter must be carefully selected to avoid a poor estimation. These measures are generally derived from the correlation integral which…

Methodology · Statistics 2024-01-09 Johan Medrano , Abderrahmane Kheddar , Annick Lesne , Sofiane Ramdani

Weak gravitational lensing surveys are rapidly becoming important tools to probe directly the mass density fluctuations in the universe and its background dynamics. Earlier studies have shown that it is possible to model the statistics of…

Astrophysics · Physics 2009-11-07 Patrick Valageas , Andrew J. Barber , Dipak Munshi

We investigate the power of wavelet techniques in detecting non-Gaussianity in the cosmic microwave background (CMB). We use the method to discriminate between an inflationary and a cosmic strings model using small simulated patches of the…

Astrophysics · Physics 2011-05-10 R. B. Barreiro , M. P. Hobson

We introduce a method for performing a robust Bayesian analysis of non-Gaussianity present in pulsar timing data, simultaneously with the pulsar timing model, and additional stochastic parameters such as those describing red spin noise and…

Instrumentation and Methods for Astrophysics · Physics 2014-09-19 Lindley Lentati , Michael P. Hobson , Paul Alexander

We present a new method to constrain local primordial non-Gaussianity using the large-scale modulation of the local lensing power spectrum. Our work extends our recently proposed $\pi$-field method for primordial non-Gaussianity estimation…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-06 Shi-Hui Zang , Moritz Münchmeyer

We study the power of several scalar quantities constructed on the sphere (presented in Monteserin et al. 2005) to detect non-Gaussianity on the temperature distribution of the cosmic microwave background (CMB). The test has been performed…

Astrophysics · Physics 2009-11-11 C. Monteserin , R. B. Barreiro , E. Martinez-Gonzalez , J. L. Sanz

Weak lensing by large-scale structure provides a unique method to directly measure matter fluctuations in the universe, and has recently been detected from the ground. Here, we report the first detection of this `cosmic shear' based on…

Astrophysics · Physics 2009-11-06 J. Rhodes , A. Refregier , E. J. Groth

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

A successful class of image denoising methods is based on Bayesian approaches working in wavelet representations. However, analytical estimates can be obtained only for particular combinations of analytical models of signal and noise, thus…

Computer Vision and Pattern Recognition · Computer Science 2016-02-02 Valero Laparra , Juan Gutiérrez , Gustavo Camps-Valls , Jesús Malo

In order to test for non-Gaussianities with respect to scale-dependencies we use so-called surrogate maps, in which possible phase correlations of the Fourier phases of the original WMAP data and simulations, respectively, are destroyed by…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 H. I. Modest , C. Räth , A. J. Banday , G. Rossmanith , R. Sütterlin , S. Basak , J. Delabrouille , K. M. Górski , G. E. Morfill

By using a simple analytical model based on counting random multiple impulses inflicted on photons by a network of cosmic strings we show how to construct the general q-point temperature correlation function of the Cosmic Microwave…

Astrophysics · Physics 2011-05-10 Alejandro Gangui , Leandros Perivolaropoulos

We present the results of a cross-correlation search for gravitational waves from SNR 1987A using the second year of LIGO Science Run 5 data. The frequency band 75--450\,Hz is searched. No evidence of gravitational waves is found. A 90\%…

General Relativity and Quantum Cosmology · Physics 2016-10-21 L. Sun , A. Melatos , P. D. Lasky , C. T. Y. Chung , N. S. Darman

We perform the stastistics of temperature maxima and minima in COBE-DMR 2-year maps. For power-law spectra the surface distribution of peaks implies an amplitude consistent with more conventional analyses of COBE data (for instance, we get…

Astrophysics · Physics 2011-05-10 R. Fabbri , S. Torres

This work investigates additional gravitational features of a newly proposed black hole spacetime within Kalb-Ramond gravity, incorporating non-commutative corrections arising from a gauge-theoretic approach recently introduced in the…

General Relativity and Quantum Cosmology · Physics 2026-05-29 A. A. Araújo Filho , N. Heidari , Iarley P. Lobo , Yuxuan Shi

Extracting non-Gaussian information from the non-linear regime of structure formation is key to fully exploiting the rich data from upcoming cosmological surveys probing the large-scale structure of the universe. However, due to theoretical…

A detection of the level of non-Gaussianity in the CMB data is essential to discriminate among inflationary models and also to test alternative primordial scenarios. However, the extraction of primordial non-Gaussianity is a difficult…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-07 A. Bernui , M. J. Reboucas , A. F. F. Teixeira
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