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Related papers: A New Approach to Probing Primordial Non-Gaussiani…

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The cosmic microwave background radiation is supposed to be Gaussian and this hypothesis is in good agreement with the recent very accurate measurements. Nonetheless a tiny amount of non-Gaussianity is predicted by the standard inflation…

Cosmology and Nongalactic Astrophysics · Physics 2009-10-06 Davide Pietrobon

The statistical properties of the primordial perturbations contain clues about the origins of those fluctuations. Although the Planck collaboration has recently obtained tight constraints on primordial non-gaussianity from cosmic microwave…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-09 Adam Lidz , Eric J. Baxter , Peter Adshead , Scott Dodelson

The fluctuations generated by Inflation are nearly Gaussian in the simplest models, but may be non-Gaussian in more complex models, potentially leading to signatures in the late Universe. In particular, local type primordial non-Gaussianity…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-03 Mponeng Kopana , Sheean Jolicoeur , Roy Maartens

Next-generation galaxy surveys will be able to measure perturbations on scales beyond the equality scale. On these ultra-large scales, primordial non-Gaussianity leaves signatures that can shed light on the mechanism by which perturbations…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-10 Mario Ballardini , William Luke Matthewson , Roy Maartens

A major goal of cosmology is to understand the nature of the field(s) which drove primordial Inflation. Through future observations, the statistics of large-scale structure will allow us to probe primordial non-Gaussianity of the curvature…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-14 Dionysios Karagiannis , Roy Maartens , Shun Saito , José Fonseca , Stefano Camera , Chris Clarkson

We propose a non-Gaussianity test for gravitational wave backgrounds by combining data streams of multiple detectors. This simple method allows us to check whether a detected background is "smooth" enough to be consistent with an…

Astrophysics · Physics 2009-11-13 Naoki Seto

We study Minkowski Functionals as probes of primordial non-Gaussianity in the Cosmic Microwave Background, specifically for the estimate of the primordial `local' bi-spectrum parameter f_NL, with instrumental parameters which should be…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Anne Ducout , François Bouchet , Stéphane Colombi , Dmitri Pogosyan , Simon Prunet

Measurements of the non-Gaussianity of the primordial density field have the power to considerably improve our understanding of the physics of inflation. Indeed, if we can increase the precision of current measurements by an order of…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-15 Matteo Tellarini , Ashley J. Ross , Gianmassimo Tasinato , David Wands

Primordial oscillatory features in the power spectrum of curvature perturbations are sensitive probes of the dynamics of the early Universe and can provide insights beyond the standard inflationary scenario. While these features have been…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-09 Mario Ballardini , Nicola Barbieri

We investigate the non-Gaussianity of primordial cosmological perturbations within our recently proposed holographic description of inflationary universes. We derive a holographic formula that determines the bispectrum of cosmological…

High Energy Physics - Theory · Physics 2011-05-16 Paul McFadden , Kostas Skenderis

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 explore the possibility of detecting primordial non-Gaussianity of the local type using weak lensing peak counts. We measure the peak abundance in sets of simulated weak lensing maps corresponding to three models f_NL={0, +100, -100}.…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-19 Laura Marian , Stefan Hilbert , Robert E. Smith , Peter Schneider , Vincent Desjacques

Using a semi-parametric approach based on the fourth-order Edgeworth expansion for the unknown signal distribution, we derive an explicit expression for the likelihood detection statistic in the presence of non-normally distributed…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Lionel Martellini , Tania Regimbau

The Universe may harbor relics of the post-inflationary epoch in the form of a network of self-ordered scalar fields. Such fossils, while consistent with current cosmological data at trace levels, may leave too weak an imprint on the cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Daniel G. Figueroa , Robert R. Caldwell , Marc Kamionkowski

Any hint of non-gaussianity in the cosmological initial conditions will provide us with a unique window into the physics of early universe. We show that the impact of a small local primordial non-gaussianity (generated on super-horizon…

Astrophysics · Physics 2008-12-18 Niayesh Afshordi , Andrew J. Tolley

Cross-correlations between Cosmic Microwave Background (CMB) temperature and $y$-spectral distortions anisotropies have been previously proposed as a way to measure the local bispectrum parameter $f_{\rm NL}^{\rm loc.}$ in a range of scales…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-04 Andrea Ravenni , Michele Liguori , Nicola Bartolo , Maresuke Shiraishi

The primordial power spectrum describes the initial perturbations in the Universe which eventually grew into the large-scale structure we observe today, and thereby provides an indirect probe of inflation or other structure-formation…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-02 P. Paykari , F. Lanusse , J. -L. Starck , F. Sureau , J. Bobin

We revisit the predictions for the expected Cosmic Microwave Background bispectrum signal from the primary-lensing-Rees-Sciama correlation; we point out that it can be a significant contaminant to the bispectrum signal from primordial…

Cosmology and Nongalactic Astrophysics · Physics 2009-12-09 Anna Mangilli , Licia Verde

We perform cosmological N-body simulations with non-Gaussian initial conditions generated from two independent fields. The dominant contribution to the perturbations comes from a purely Gaussian field, but we allow the second field to have…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-25 Saroj Adhikari , Sarah Shandera , Neal Dalal

We investigate future constraints on primordial local-type non-Gaussianity from 21 cm angular power spectrum from minihalos. We particularly focus on the trispectrum of primordial curvature perturbations which are characterized by the…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-27 Toyokazu Sekiguchi , Tomo Takahashi , Hiroyuki Tashiro , Shuichiro Yokoyama