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Cosmic magnetic fields are observed to be coherent on large scales and could have a primordial origin. Non-Gaussian signals in the cosmic microwave background (CMB) are generated by primordial magnetic fields as the magnetic stresses and…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-05 Pranjal Trivedi , Kandaswamy Subramanian , T. R. Seshadri

We study the impact of cosmological parameters' uncertainties on estimates of the primordial NG parameter f_NL in local and equilateral models of non-Gaussianity. We show that propagating these errors increases the f_NL relative uncertainty…

Astrophysics · Physics 2008-12-30 M. Liguori , 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

We study nonlinear cosmological perturbations and their possible non-Gaussian character in an extended non-minimal inflation where gravity is coupled non-minimally to both the scalar field and its derivatives. By expansion of the action up…

General Relativity and Quantum Cosmology · Physics 2019-10-09 Raheleh Shojaee , Kourosh Nozari , Farhad Darabi

We investigate the observational signatures of three models of the early Universe in the $B$-mode polarization of the Cosmic Microwave Background (CMB) radiation. In addition to the standard single field inflationary model, we also consider…

Cosmology and Nongalactic Astrophysics · Physics 2011-01-27 Yin-Zhe Ma , Wen Zhao , Michael L. Brown

With future galaxy surveys, a huge number of Fourier modes of the distribution of the large scale structures in the Universe will become available. These modes are complementary to those of the CMB and can be used to set constraints on…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-20 Zhiqi Huang , Licia Verde , Filippo Vernizzi

The assumption of Gaussianity of the primordial perturbations plays an important role in modern cosmology. The most direct test of this hypothesis consists in testing Gaussianity of the CMB maps. Counting the pixels with the temperatures in…

Astrophysics · Physics 2011-05-10 Sergei F. Shandarin

Non-Gaussian statistics in the distribution of large scale structure, and in temperature fluctuations of the cosmic microwave background, can be used to constrain inflationary models. Data on the cosmic microwave background from Planck…

General Relativity and Quantum Cosmology · Physics 2018-03-06 Nick Woods

We investigate how well the SPHEREx all-sky survey can constrain local primordial non-Gaussianity beyond the parameter $f_{\text{NL}}$ using galaxy power spectra. We forecast joint constraints on the parameters $f_{\text{NL}}$,…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-16 Charuhas Shiveshwarkar , Thejs Brinckmann , Marilena Loverde

We analyze non-Gaussianity (NG) due to the primordial bispectrum and trispectrum using CMB temperature maps of WMAP 7-year data. We first apply the perturbative formulae of Minkowski functionals up to second-order NG derived by Matsubara…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-28 Chiaki Hikage , Takahiko Matsubara

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

We present forecasts on the primordial non-Gaussianity parameter $f_\text{NL}$ of feature models for the future Cosmic Microwave Background Stage-4 (CMB-S4) experiments. The Fisher matrix of the bispectrum estimator was computed using noise…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-02 Wuhyun Sohn , James Fergusson

Galaxy bispectrum is a promising probe of inflationary physics in the early universe as a measure of primordial non-Gaussianity (PNG), whereas its signal-to-noise ratio is significantly affected by the mode coupling due to non-linear…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-13 Masato Shirasaki , Naonori S. Sugiyama , Ryuichi Takahashi , Francisco-Shu Kitaura

The search for primordial non-Gaussianities (PNG) is theoretically well motivated but remains observationally challenging. Tight constraints with low significance for the standard non-Gaussian shapes suggest that detection may lie beyond…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-24 Petar Suman , Dong-Gang Wang , Wuhyun Sohn , James R. Fergusson , E. P. S. Shellard

We compute the amplitude of the non-Gaussianities in inflationary models with multiple, uncoupled scalar fields. This calculation thus applies to all models of assisted inflation, including N-flation, where inflation is driven by multiple…

Astrophysics · Physics 2010-10-27 Thorsten Battefeld , Richard Easther

Primordial non-Gaussianity (PNG) is a signature of fundamental physics in the early universe that is probed by cosmological observations. It is well known that the local type of PNG generates a strong signal in the two-point function of…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-28 James M. Sullivan , Uros Seljak

Inflationary cosmology with a preceding nonsingular bounce can lead to changes on the primordial density fluctuations. One significant prediction is that the amplitude of the power spectrum may undergo a jump at a critical scale. In this…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-10 Jie Liu , Yi-Fu Cai , Hong Li

We compute the three-point correlation function of primordial scalar density perturbations in a general single-field inflationary scenario, where a scalar field phi has a direct coupling with the Ricci scalar R and the Gauss-Bonnet term GB.…

Cosmology and Nongalactic Astrophysics · Physics 2011-04-22 Antonio De Felice , Shinji Tsujikawa

We show a primordial non-linear "f_NL" term may produce unphysically large CMB anisotropy for a red-tilted primordial power spectrum (n<1), because of coupling to primordial fluctuation on the largest scale. We consider a primordial power…

Cosmology and Nongalactic Astrophysics · Physics 2009-06-14 Jaiseung Kim , Pavel Naselsky

We study scale dependence of the cosmic microwave background (CMB) power spectrum in a class of small, single-field models of inflation which lead to a high value of the tensor to scalar ratio. The inflaton potentials that we consider are…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-28 Ira Wolfson , Ram Brustein
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