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Non-Gaussianity in the inflationary perturbations can couple observable scales to modes of much longer wavelength (even superhorizon), leaving as a signature a large-angle modulation of the observed cosmic microwave background (CMB) power…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Fabian Schmidt , Lam Hui

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 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

Primordial magnetic fields will generate non-Gaussian signals in the cosmic microwave background (CMB) as magnetic stresses and the temperature anisotropy they induce depend quadratically on the magnetic field. We compute a new measure of…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-15 Pranjal Trivedi , T. R. Seshadri , Kandaswamy Subramanian

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.…

Astrophysics · Physics 2007-10-16 E. Jeong , G. F. Smoot

Here we review the present status of modelling of and searching for primordial non-Gaussianity of cosmological perturbations. After introducing the models for non-Gaussianity generation during inflation, we discuss the search for…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-21 Marco Celoria , Sabino Matarrese

We review the current status of the cosmic microwave background (CMB) radiation, including a brief discussion of some basic theoretical aspects as well as a summary of anisotropy detections and CMB experiments. We focus on the description…

Astrophysics · Physics 2011-05-10 R. B. Barreiro

Primordial magnetic fields (PMFs) create a large squeezed-type non-Gaussianity in tensor perturbation, which generates non-Gaussian temperature fluctuations in the cosmic microwave background (CMB). We for the first time derive an…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-13 Maresuke Shiraishi , Toyokazu Sekiguchi

In the context of the present and future Cosmic Microwave Background (CMB) experiments, going beyond the information provided by the power spectrum has become necessary in order to tightly constrain the cosmological model. The non-Gaussian…

Astrophysics · Physics 2008-11-26 N. Aghanim , M. Kunz , P. G. Castro , O. Forni

Two recent papers have claimed detection of non-Gaussian features in the COBE DMR sky maps of the cosmic microwave background. We confirm these results, but argue that Gaussianity is still not convincingly ruled out. Since a score of…

Astrophysics · Physics 2009-10-31 Benjamin C. Bromley , Max Tegmark

Gaussianity is the very base for derivation of the cosmological parameters from the CMB angular power spectrum. Non-Gaussian signal, whether originated from experimental error or primordial source, could mimic extra power in the power…

Astrophysics · Physics 2009-11-11 Pavel Naselsky , Lung-Yih Chiang , Poul Olesen , Igor Novikov

We present an upgraded combined estimator, based on Minkowski Functionals and Neural Networks, with excellent performance in detecting primordial non-Gaussianity in simulated maps that also contain a weighted mixture of Galactic…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-07 C. P. Novaes , A. Bernui , I. S. Ferreira , C. A. Wuensche

Cosmological phase transitions in the primordial universe can produce anisotropic stochastic gravitational wave backgrounds (GWB), similar to the cosmic microwave background (CMB). For adiabatic perturbations, the fluctuations in GWB follow…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-01 Soubhik Kumar , Raman Sundrum , Yuhsin Tsai

To minimize instrumentally induced systematic errors, cosmic microwave background (CMB) anisotropy experiments measure temperature differences across the sky using paires of horn antennas, temperature map is recovered from temperature…

Astrophysics · Physics 2009-08-30 Hao Liu , Ti-Pei Li

[Abridged.] It is conceivable that no single statistical estimator can be sensitive to all forms and levels of non-Gaussianity that may be present in observed CMB data. In recent works a statistical procedure based upon the calculation of…

Cosmology and Nongalactic Astrophysics · Physics 2015-01-14 A. Bernui , M. J. Reboucas

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…

Astrophysics · Physics 2009-11-11 P. Cabella , F. K. Hansen , M. Liguori , D. Marinucci , S. Matarrese , L. Moscardini , N. Vittorio

Noncommutative geometry can provide effective description of physics at very short distances taking into account generic effects of quantum gravity. Inflation amplifies tiny quantum fluctuations in the early universe to macroscopic scales…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-18 Tomi S. Koivisto , David F. Mota

In this work we effectively calculated the two-dimensional Minkowski functionals for cosmic microwave background (CMB) temperature maps generated by single field models of inflation with a standard kinetic term. We started with calculation…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-25 M. Junaid , D. Pogosyan

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…

Recent measurements of the temperature fluctuations of the cosmic microwave background (CMB) radiation from the WMAP satellite provide indication of a non-Gaussian behavior. Although the observed feature is small, it is detectable and…

Astrophysics · Physics 2008-11-26 Armando Bernui , Constantino Tsallis , Thyrso Villela
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