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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

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

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

It is possible to classify pixels of a smoothed cosmic microwave background (CMB) fluctuation map according to their local curvature in ``hill'', ``lake'' and ``saddle'' regions. In the Gaussian case, fractional areas occupied by pixels of…

天体物理学 · 物理学 2011-05-10 O. Doré , S. Colombi , F. R. Bouchet

We study statistical anisotropies generated in the observed two-point function of the cosmic microwave background (CMB) fluctuations if the primordial statistics are non-Gaussian. Focusing on the dipole modulations of the anisotropies, we…

宇宙学与河外天体物理 · 物理学 2018-07-17 Saroj Adhikari , Anne-Sylvie Deutsch , Sarah Shandera

We study signatures in the Cosmic Microwave Background (CMB) induced by the presence of strong spatial curvature prior to the epoch of inflation which generated our present universe. If inflation does not last sufficiently long to drive the…

宇宙学与河外天体物理 · 物理学 2010-02-02 Tim Clunan , David Seery

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

We propose a new method for extracting the non-Gaussian signatures on the isotemperature statistics in the cosmic microwave background (CMB) sky, which is induced by the gravitational lensing due to the intervening large-scale structure of…

天体物理学 · 物理学 2009-11-06 Masahiro Takada

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

Cross-correlations between Cosmic Microwave Background (CMB) temperature and $y$-spectral distortions anisotropies have been previously proposed as a way to measure the local bispectrum parameter $f_{\rm NL}^{\rm loc.}$ in a range of scales…

宇宙学与河外天体物理 · 物理学 2017-10-04 Andrea Ravenni , Michele Liguori , Nicola Bartolo , Maresuke Shiraishi

The cosmic microwave background (CMB) temperature bispectrum is currently the most precise tool for constraining primordial non-Gaussianity (NG). The Planck temperature data tightly constrain the amplitude of local-type NG: $f_{\rm NL}^{\rm…

宇宙学与河外天体物理 · 物理学 2018-11-06 J. Colin Hill

We study the degree to which the cosmic microwave background (CMB) can be used to constrain primordial non-Gaussianity involving one tensor and two scalar fluctuations, focusing on the correlation of one polarization $B$ mode with two…

宇宙学与河外天体物理 · 物理学 2016-06-15 P. Daniel Meerburg , Joel Meyers , Alex van Engelen , Yacine Ali-Haïmoud

We introduce the numbers of hot and cold spots, $n_h$ and $n_c$, of excursion sets of the CMB temperature anisotropy maps as statistical observables that can discriminate different non-Gaussian models. We numerically compute them from…

宇宙学与河外天体物理 · 物理学 2015-06-05 Pravabati Chingangbam , Changbom Park , K. P. Yogendran , Rien van de Weygaert

[Abridged]: A detection or nondetection of primordial non-Gaussianity by using the CMB data is crucial not only to discriminate inflationary models but also to test alternative scenarios. Non-Gaussianity offers, therefore, a powerful probe…

宇宙学与河外天体物理 · 物理学 2010-04-14 A. Bernui , M. J. Reboucas

We present a Gaussianity analysis of the Archeops Cosmic Microwave Background (CMB) temperature anisotropy data maps at high resolution to constrain the non-linear coupling parameter fnl characterising well motivated non-Gaussian CMB…

We describe and discuss the application of Gumbel statistics, which model extreme events, to WMAP 5-year measurements of the cosmic microwave background. We find that temperature extrema of the CMB are well modelled by the Gumbel formalism…

宇宙学与河外天体物理 · 物理学 2015-06-01 Gatis Mikelsons , Joseph Silk , Joe Zuntz

Galaxy cluster surveys will be a powerful probe of dark energy. At the same time, cluster abundance is sensitive to any non-Gaussianity of the primordial density field. It is therefore possible that non-Gaussian initial conditions might be…

天体物理学 · 物理学 2010-11-05 Emiliano Sefusatti , Chris Vale , Kenji Kadota , Joshua Frieman

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…

天体物理学 · 物理学 2010-11-19 Frode K. Hansen , Domenico Marinucci , Nicola Vittorio

The next generation of CMB experiments should get a better handle on cosmological parameters by mapping the weak lensing deflection field, which is separable from primary anisotropies thanks to the non-Gaussianity induced by lensing.…

天体物理学 · 物理学 2009-11-10 Julien Lesgourgues , Michele Liguori , Sabino Matarrese , Antonio Riotto

We analyze WMAP 3 year data using the one-point distribution functions to probe the non-Gaussianity in the Cosmic Microwave Background (CMB) Anisotropy data. Computer simulations are performed to determine the uncertainties of the results.…

天体物理学 · 物理学 2007-10-16 E. Jeong , G. F. Smoot
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