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We present a detailed implementation of two bispectrum estimation methods which can be applied to general non-separable primordial and CMB bispectra. The method exploits bispectrum mode decompositions on the domain of allowed wavenumber or…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 J. R. Fergusson , M. Liguori , E. P. S. Shellard

Recent second-order perturbation computations have provided an accurate prediction for the primordial gravitational potential $\Phi(x)$ in scenarios in which cosmological perturbations are generated either during or after inflation. This…

Astrophysics · Physics 2008-11-26 M. Liguori , F. K. Hansen , E. Komatsu , S. Matarrese , A. Riotto

We study the effects of instrumental systematics on the estimation of primordial non-Gaussianity using the cosmic microwave background (CMB) bispectrum from both the temperature and the polarization anisotropies. For temperature systematics…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-07 Meng Su , Amit P. S. Yadav , Meir Shimon , Brian G. Keating

The primordial non-Gaussianity parameters fNL and tauNL may be scale-dependent. We investigate the capability of future measurements of the CMB mu-distortion, which is very sensitive to small scales, and of the large-scale halo bias to test…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-27 Matteo Biagetti , Hideki Perrier , Antonio Riotto , Vincent Desjacques

We discuss the non-Gaussian contribution to the power spectrum covariance of cosmic microwave background (CMB) anisotropies resulting through weak gravitational lensing angular deflections and the correlation of deflections with secondary…

Astrophysics · Physics 2009-11-07 Asantha Cooray

We use simulated maps of the cosmic microwave background anisotropy to quantify the ability of different statistical tests to discriminate between Gaussian and non-Gaussian models. Despite the central limit theorem on large angular scales,…

Astrophysics · Physics 2009-10-31 Nicholas G. Phillips , A. Kogut

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 investigate expected constraints on equilateral-type primordial non-Gaussianities from future/ongoing imaging surveys, making use of the fact that they enhance the halo/galaxy bispectrum on large scales. As model parameters to be…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-31 Ichihiko Hashimoto , Shuntaro Mizuno , Shuichiro Yokoyama

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…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-15 Zahra Gomes , Stefano Camera , Matt J. Jarvis , Catherine Hale , José Fonseca

We look for a non-Gaussian signal in the WMAP 5-year temperature anisotropy maps by performing a needlet-based data analysis. We use the foreground-reduced maps obtained by the WMAP team through the optimal combination of the W, V and Q…

We describe different methods for estimating the bispectrum of Cosmic Microwave Background data. In particular we construct a minimum variance estimator for the flat-sky limit and compare results with previously-studied frequentist methods.…

A description of CMB temperature fluctuations beyond the power spectrum is important for verifying models of structure formation, especially in view of forthcoming high-resolution observations. We argue that higher-order statistics of…

Astrophysics · Physics 2007-05-23 S. Winitzki , J. H. P. Wu

We present a set of formalisms for comparing, evolving and constraining primordial non-Gaussian models through the CMB bispectrum. We describe improved methods for efficient computation of the full CMB bispectrum for any general…

Astrophysics · Physics 2009-09-02 J. R. Fergusson , E. P. S. Shellard

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…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Guido W. Pettinari , Christian Fidler , Robert Crittenden , Kazuya Koyama , David Wands

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…

Cosmology and Nongalactic Astrophysics · Physics 2012-02-15 A. Bernui , M. J. Reboucas , A. F. F. Teixeira

In the conference presentation we have reviewed the theory of non-Gaussian geometrical measures for the 3D Cosmic Web of the matter distribution in the Universe and 2D sky data, such as Cosmic Microwave Background (CMB) maps that was…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-19 Dmitri Pogosyan , Sandrine Codis , Christophe Pichon

Primordial gravitational waves could be non-Gaussian, just like primordial scalar perturbations. Although the tensor two-point function has thus-far remained elusive, the three-point function could, in principle, be large enough to be…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-14 Oliver H. E. Philcox , Maresuke Shiraishi

We use data from the WMAP temperature maps to constrain a scale-dependent generalization of the popular 'local' model for primordial non-Gaussianity. In the model where the parameter fNL is allowed to run with scale k, fNL(k) = fNL*…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-16 Adam Becker , Dragan Huterer

We present evidence for the detection of primordial non-Gaussianity of the local type (fNL), using the temperature information of the Cosmic Microwave Background (CMB) from the WMAP 3-year data. We employ the bispectrum estimator of…

Astrophysics · Physics 2008-11-26 Amit P. S. Yadav , Benjamin D. Wandelt

In this paper we analyze the biasing effect of point sources, either thermal Sunyaev-Zeldovich clusters or standard radio sources, on the estimated strength of the non-Gaussianity in the Cosmic Microwave Background (CMB). We show that the…

Astrophysics · Physics 2008-11-26 Daniel Babich , Elena Pierpaoli
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