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It is the aim of this paper to introduce the use of isotropic wavelets to detect and determine the flux of point sources appearing in CMB maps. The most suited wavelet to detect point sources filtered with a Gaussian beam is the Mexican…

In this draft we comment on the results concerning the performances of matched filters, scale adaptive filters and Mexican hat wavelet that recently appeared in literature in the context of point source detection in Cosmic Microwave…

天体物理学 · 物理学 2009-11-07 Roberto Vio , Paola Andreani , Willelm Wamsteker

After the precise observations of the Cosmic Microwave Background (CMB) anisotropy power spectrum, attention is now being focused on the higher order statistics of the CMB anisotropies. Since linear evolution preserves the statistical…

天体物理学 · 物理学 2009-11-10 Daniel Babich , Matias Zaldarriaga

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…

宇宙学与河外天体物理 · 物理学 2025-08-28 Jorik Melsen , Thomas Flöss , P. Daniel Meerburg

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…

天体物理学 · 物理学 2009-11-11 P. Cabella , F. K. Hansen , M. Liguori , D. Marinucci , S. Matarrese , L. Moscardini , N. Vittorio

The cosmic microwave background radiation is supposed to be Gaussian and this hypothesis is in good agreement with the recent very accurate measurements. Nonetheless a tiny amount of non-Gaussianity is predicted by the standard inflation…

宇宙学与河外天体物理 · 物理学 2009-10-06 Davide Pietrobon

We generalize the concept of the ordinary skew-spectrum to probe the effect of non-Gaussianity on the morphology of Cosmic Microwave Background (CMB) maps in several domains: in real-space (where they are commonly known as…

宇宙学与河外天体物理 · 物理学 2015-05-20 Dipak Munshi , Joseph Smidt , Asantha Cooray , Alessandro Renzi , Alan Heavens , Peter Coles

We use the full bispectrum of spherical needlets applied to the WMAP data of the cosmic microwave background as an estimator for the primordial non-Gaussianity parameter f_NL. We use needlet scales up to l_max=1000 and the KQ75 galactic cut…

宇宙学与河外天体物理 · 物理学 2009-08-11 Oystein Rudjord , Frode K. Hansen , Xiaohong Lan , Michele Liguori , Domenico Marinucci , Sabino Matarrese

Since cosmic-microwave-background (CMB) and large-scale-structure (LSS) data will shortly improve dramatically with the Microwave Anisotropy Probe (MAP) and Planck Surveyor, and the Anglo-Australian 2-Degree Field (2dF) and Sloan Digital…

天体物理学 · 物理学 2009-10-31 Licia Verde , Limin Wang , Alan Heavens , Marc Kamionkowski

A detection or non detection of primordial non--Gaussianity (NG) by using the cosmic microwave background radiation (CMB) is a possible way to break the degeneracy of early universe models. Since a single statistical estimator hardly can be…

宇宙学与河外天体物理 · 物理学 2013-05-29 W. A. Cardona , A. Bernui , M. J. Reboucas

In this work we analyze the effect of smoothing maps containing arrival directions of cosmic rays with a gaussian kernel and kernels of the mexican hat wavelets of orders 1, 2 and 3. The analysis is performed by calculating the…

天体物理仪器与方法 · 物理学 2015-05-30 Rafael Alves Batista , Ernesto Kemp , Bruno Daniel

We use the statistics of regions above or below a temperature threshold (excursion sets) to study the cosmic microwave background (CMB) anisotropy in models with primordial non-Gaussianity of the local type. By computing the full-sky…

宇宙学与河外天体物理 · 物理学 2015-05-18 Graziano Rossi , Pravabati Chingangbam , Changbom Park

We introduce an exact Bayesian approach to search for non-Gaussianity of local type in Cosmic Microwave Background (CMB) radiation data. Using simulated CMB temperature maps, the newly developed technique is compared against the…

宇宙学与河外天体物理 · 物理学 2010-11-15 Franz Elsner , Benjamin D. Wandelt

Over the last few years, needlets have a emerged as a useful tool for the analysis of Cosmic Microwave Background (CMB) data. Our aim in this paper is first to introduce in the CMB literature a different form of needlets, known as Mexican…

宇宙学与河外天体物理 · 物理学 2011-08-29 S. Scodeller , O. Rudjord , F. K. Hansen , D. Marinucci , D. Geller , A. Mayeli

The decomposition of a signal on the sphere with the steerable wavelet constructed from the second Gaussian derivative gives access to the orientation, signed-intensity, and elongation of the signal's local features. In the present work,…

天体物理学 · 物理学 2009-11-13 Y. Wiaux , P. Vielva , R. B. Barreiro , E. Martinez-Gonzalez , P. Vandergheynst

We consider wavelets as a tool to perform a variety of tasks in the context of analyzing cosmic microwave background (CMB) maps. Using Spherical Haar Wavelets we define a position and angular-scale-dependent measure of power that can be…

天体物理学 · 物理学 2009-10-31 L. Tenorio , A. H. Jaffe , S. Hanany , C. H. Lineweaver

We outline the expected constraints on non-Gaussianity from the cosmic microwave background (CMB) with current and future experiments, focusing on both the third (f_{NL}) and fourth-order (g_{NL} and \tau_{NL}) amplitudes of the local…

宇宙学与河外天体物理 · 物理学 2010-07-27 Joseph Smidt , Alexandre Amblard , Christian T. Byrnes , Asantha Cooray , Alan Heavens , Dipak Munshi

A detection or nondetection of primordial non-Gaussianity by using the cosmic microwave background radiation (CMB) offers a way of discriminating inflationary scenarios and testing alternative models of the early universe. This has…

宇宙学与河外天体物理 · 物理学 2012-02-15 A. Bernui , M. J. Reboucas , A. F. F. Teixeira

We present a maximum-entropy method (MEM) and `Mexican Hat' wavelet (MHW) joint analysis to recover the different components of the microwave sky from simulated observations by the ESA Planck satellite in a small patch of the sky. This…

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…

宇宙学与河外天体物理 · 物理学 2011-11-09 Kendrick M. Smith