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相关论文: An improved estimator for non-Gaussianity in cosmi…

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We measure the skewness power spectrum of the Cosmic Microwave Background (CMB) anisotropies optimized for a detection of the secondary bispectrum generated by the correlation of the CMB lensing potential with integrated Sachs-Wolfe effect…

宇宙学与河外天体物理 · 物理学 2013-05-29 Erminia Calabrese , Joseph Smidt , Alexandre Amblard , Asantha Cooray , Alessandro Melchiorri , Paolo Serra , Alan Heavens , Dipak Munshi

We describe a new numerical algorithm to obtain high-resolution simulated maps of the Cosmic Microwave Background (CMB), for a broad class of non-Gaussian models. The kind of non-Gaussianity we account for is based on the simple idea that…

天体物理学 · 物理学 2009-11-07 Michele Liguori , Sabino Matarrese , Lauro Moscardini

In this work we present a method to extract the signal induced by the integrated Sachs-Wolfe (ISW) effect in the cosmic microwave background (CMB). It makes use of the Linear Covariance-Based filter introduced by Barreiro et al., and…

宇宙学与河外天体物理 · 物理学 2016-03-09 L. Bonavera , R. B. Barreiro , A. Marcos-Caballero , P. Vielva

We develop a new, efficient code for solving the second-order Einstein-Boltzmann equations, and use it to estimate the intrinsic CMB non-Gaussianity arising from the non-linear evolution of density perturbations. The full calculation…

宇宙学与河外天体物理 · 物理学 2015-06-12 Guido W. Pettinari , Christian Fidler , Robert Crittenden , Kazuya Koyama , David Wands

We use quadratic maximum-likelihood (QML) estimators to constrain models with Gaussian but statistically anisotropic Cosmic Microwave Background (CMB) fluctuations, using CMB maps with realistic sky-coverage and instrumental noise. This…

宇宙学与河外天体物理 · 物理学 2012-03-06 Duncan Hanson , Antony Lewis

A new method for removing point radio sources and other non-Gaussian noise is proposed as a means of improving the accuracy of estimates of the angular power spectrum of the cosmic microwave background (CMB). The main idea of the method is…

天体物理学 · 物理学 2009-11-13 Anisa T. Bajkova

We calculate the cosmic microwave background (CMB) bispectrum due to inhomogeneous reionization. We calculate all the terms that can contribute to the bispectrum that are products of first order terms on all scales in conformal Newtonian…

宇宙学与河外天体物理 · 物理学 2014-11-20 Rishi Khatri , Benjamin D. Wandelt

We use a separable mode expansion estimator with WMAP data to estimate the bispectrum for all the primary families of non-Gaussian models. We review the late-time mode expansion estimator methodology which can be applied to any…

宇宙学与河外天体物理 · 物理学 2015-05-19 J. R. Fergusson , M. Liguori , E. P. S. Shellard

Tighter constraints on measurements of primordial non-Gaussianity will allow the differentiation of inflationary scenarios. The cosmic microwave background bispectrum-the standard method of measuring the local non-Gaussianity-is limited by…

宇宙学与河外天体物理 · 物理学 2020-09-15 Zahra Gomes , Stefano Camera , Matt J. Jarvis , Catherine Hale , José Fonseca

We present a new method based on the N-point probability distribution (pdf) to study non-Gaussianity in cosmic microwave background (CMB) maps. Likelihood and Bayesian estimation are applied to a local non-linear perturbed model up to third…

天体物理学 · 物理学 2015-05-13 P. Vielva , J. L. Sanz

We present an implementation of an optimal CMB trispectrum estimator which accounts for anisotropic noise and incomplete sky coverage. We use a general separable mode expansion which can and has been applied to constrain both primordial and…

宇宙学与河外天体物理 · 物理学 2010-12-30 J. R. Fergusson , D. M. Regan , E. P. S. Shellard

The Cosmic Microwave Background (CMB) is a fundamental observational tool in modern cosmology. The linear polarization of the CMB provides a crucial observational tool for exploring new physics, including the inflationary paradigm and…

宇宙学与河外天体物理 · 物理学 2025-03-12 Vyoma Muralidhara

When constraining the primordial non-Gaussianity parameter f_NL with cosmic microwave background anisotropy maps, the bias resulting from the covariance between primordial non-Gaussianity and secondary non-Gaussianities to the estimator of…

天体物理学 · 物理学 2008-11-26 Paolo Serra , Asantha Cooray

The lensing convergence field describing the weak lensing effect of the Cosmic Microwave Background (CMB) radiation is expected to be subject to mild deviations from Gaussianity. We perform a suite of full-sky lensing simulations using ray…

宇宙学与河外天体物理 · 物理学 2025-03-18 Jan Hamann , Yuqi Kang

Searching for and charactering the non-Gaussianity (NG) of a given field has been a vital task in many fields of science, because we expect the consequences of different physical processes to carry different statistical properties. Here we…

天体物理学 · 物理学 2007-05-23 Jiun-Huei Proty Wu

The trispectrum of the cosmic microwave background can be used to assess the level of non-Gaussianity on cosmological scales. It probes the fourth order moment, as a function of angular scale, of the probability distribution function of…

We present a novel approach to estimate the value of primordial non-Gaussianity ($f_{\rm NL}$) parameter directly from the Cosmic Microwave Background (CMB) maps using a convolutional neural network (CNN). While traditional methods rely on…

宇宙学与河外天体物理 · 物理学 2024-03-26 Chandan G. Nagarajappa , Yin-Zhe Ma

We present a new, model-independent approach for measuring non-Gaussianity of the Cosmic Microwave Background (CMB) anisotropy pattern. Our approach is based on the empirical distribution function of the normalized spherical harmonic…

天体物理学 · 物理学 2011-05-10 Frode K. Hansen , Domenico Marinucci , Paolo Natoli , Nicola Vittorio

We compute the fully non-linear Cosmic Microwave Background (CMB) anisotropies on scales larger than the horizon at last-scattering in terms of only the curvature perturbation, providing a generalization of the linear Sachs-Wolfe effect at…

天体物理学 · 物理学 2009-11-13 N. Bartolo , S. Matarrese , A. Riotto

The gravitational lensing signal from the Cosmic Microwave Background is highly valuable to constrain the growth of the structures in the Universe in a clean and robust manner over a wide range of redshifts. One of the theoretical…

宇宙学与河外天体物理 · 物理学 2024-07-02 Omar Darwish , Sebastian Belkner , Louis Legrand , Julien Carron , Giulio Fabbian