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The fluctuations produced during cosmic inflation may exhibit non-Gaussian characteristics that are imprinted in the large-scale structure of the Universe. This non-Gaussian imprint is an ultra-large scale signal that can be detected using…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-11 Mponeng Kopana , Sheean Jolicoeur , Roy Maartens

We investigate whether non-adiabatic perturbations from inflation could produce an asymmetric distribution of temperature anisotropies on large angular scales in the cosmic microwave background (CMB). We use a generalised non-linear $\delta…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Hooshyar Assadullahi , Hassan Firouzjahi , Mohammad Hossein Namjoo , David Wands

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

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…

Astrophysics · Physics 2009-11-06 Masahiro Takada

Observations of the Cosmic Microwave Background (CMB) have cemented the notion that the large-scale Universe is both statistically homogeneous and isotropic. But is it invariant also under reflections? To probe this we require…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-25 Oliver H. E. Philcox

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…

Astrophysics · Physics 2011-05-10 O. Doré , S. Colombi , F. R. Bouchet

We study non-Gaussian signatures on the cosmic microwave background (CMB) radiation predicted within inflationary models with non-vacuum initial states for cosmological perturbations. The model incorporates a privileged scale, which implies…

Astrophysics · Physics 2008-11-26 Alejandro Gangui , Jerome Martin , Mairi Sakellariadou

We compute cosmic microwave background (CMB) anisotropy constraints on exotic forms of energy injection in electromagnetic (e.m.) channels over a large range of timescales. These constraints are very powerful around or just after…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-28 Vivian Poulin , Julien Lesgourgues , Pasquale D. Serpico

Observations show that the Cosmic Microwave Background (CMB) contains tiny variations at the 10^{-5} level around its black-body equilibrium temperature. The detection of these temperature fluctuations provides to modern Cosmology evidence…

Astrophysics · Physics 2015-06-24 Armando Bernui

We investigate the degree to which the Cosmic Microwave Background (CMB) can be used to constrain primordial non-Gaussianity coming from the presence of spinning particles coupled to the inflaton. We compute the $\langle TTT \rangle$ and…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-09 Lorenzo Bordin , Giovanni Cabass

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

The redshifted 21-cm emission by neutral hydrogen offers a unique tool for mapping structure formation in the early universe in three dimensions. Here we provide the first detailed calculation of the 21-cm emission signal during and after…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Anastasia Fialkov , Abraham Loeb

In this paper we present a complete computation of the Cosmic Microwave Background (CMB) anisotropies up to third order from gravitational perturbations accounting for scalar, vector and tensor perturbations. We then specify our results to…

Astrophysics · Physics 2008-11-26 G. D'Amico , N. Bartolo , S. Matarrese , A. Riotto

A detection or nondetection of primordial non-Gaussianity in the CMB data is essential not only to test alternative models of the physics of the early universe but also to discriminate among classes of inflationary models. Given this far…

Cosmology and Nongalactic Astrophysics · Physics 2010-09-15 A. Bernui , M. J. Reboucas

Minimum-variance estimators for the parameter fnl that quantifies local-model non-Gaussianity can be constructed from the cosmic microwave background (CMB) bispectrum (three-point function) and also from the trispectrum (four-point…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-03 Marc Kamionkowski , Tristan L. Smith , Alan Heavens

Primordial magnetic fields lead to non-Gaussian signals in the cosmic microwave background (CMB) even at the lowest order, as magnetic stresses and the temperature anisotropy they induce depend quadratically on the magnetic field. In…

Cosmology and Nongalactic Astrophysics · Physics 2011-01-17 Pranjal Trivedi , Kandaswamy Subramanian , T. R. Seshadri

The cross-correlation between the cosmic microwave background (CMB) fields and matter tracers carries important cosmological information. In this paper, we forecast by a signal-to-noise ratio analysis the information contained in the…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-10 José R. Bermejo-Climent , Mario Ballardini , Fabio Finelli , Daniela Paoletti , Roy Maartens , José A. Rubiño-Martin , Luca Valenziano

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…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-12 Vyoma Muralidhara

The primordial non-Gaussianity of local type affects the clustering of dark matter halos, and the planned deep and wide photometric surveys are suitable for examining this class of non-Gaussianity. In our previous paper, we investigated the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Yoshitaka Takeuchi , Kiyotomo Ichiki , Takahiko Matsubara

The presence of a dipolar statistical anisotropy in the spectrum of cosmic microwave background (CMB) fluctuations was reported by the Wilkinson Microwave Anisotropy Probe (WMAP), and has recently been confirmed in the Planck 2013 analysis…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-29 Sugumi Kanno , Misao Sasaki , Takahiro Tanaka