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Related papers: Loop-Induced Stochastic Bias at Small Wavevectors

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We consider the 3-pt function (i.e. the bispectrum or non-Gaussianity) for stochastic backgrounds of gravitational waves. We estimate the amplitude of this signal for the primordial inflationary background, gravitational waves generated…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Peter Adshead , Eugene A. Lim

As one of the promising candidates of cold dark matter (DM), primordial black holes (PBHs) were formed due to the collapse of over-densed regions generated by the enhanced curvature perturbations during the radiation-dominated era. The…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-21 De-Shuang Meng , Chen Yuan , Qing-guo Huang

We investigate the impact of early-time initial conditions on nonlinear structure formation and evolution within the framework of the semi-analytical Excursion Set Theory (EST). Our analysis reveals that adding a Gaussian bump to the…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-17 Hamed Kameli , Shant Baghram

The redshift dependence of the abundance of galaxy clusters is very sensitive to the statistical properties of primordial density perturbations. It can thus be used to probe small deviations from Gaussian initial conditions. Such deviations…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 A. M. M. Trindade , P. P. Avelino , P. T. P. Viana

The inflationary 1-loop tensor power spectrum from an excited spectator scalar field is calculated. Recent studies on primordial black holes suggest that the inflationary curvature perturbation may be huge on small scales. An enhanced…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-03 Atsuhisa Ota , Misao Sasaki , Yi Wang

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

Local non-Gaussianity, parametrized by $f_{\rm NL}$, introduces a scale-dependent bias that is strongest at large scales, precisely where General Relativistic (GR) effects also become significant. With future data, it should be possible to…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Marco Bruni , Robert Crittenden , Kazuya Koyama , Roy Maartens , Cyril Pitrou , David Wands

We calculate the curvature power spectrum sourced by spectator fields that are excited repeatedly and non-adiabatically during inflation. In the absence of detailed information of the nature of spectator field interactions, we consider an…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-01 Marcos A. G. Garcia , Mustafa A. Amin , Daniel Green

Primordial non-Gaussianities of the scalar(tensor)-tensor-tensor type supporting a non-trivial squeezed component are known to induce anisotropies in the stochastic gravitational wave background. We derive the explicit form of such…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-23 Ema Dimastrogiovanni , Matteo Fasiello , Lucas Pinol

Primordial non-Gaussianities from multi-field inflation are a leading target for cosmological observations, because of the possible large correlations generated between long and short distances. These signatures are captured by the local…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-31 Dong-Gang Wang , Guilherme L. Pimentel , Ana Achúcarro

We show that the contribution of the primordial trispectrum to the energy density of the scalar-induced stochastic gravitational wave background cannot exceed the one from the scalar power spectrum in conventional inflationary scenarios.…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-05 Sebastian Garcia-Saenz , Lucas Pinol , Sébastien Renaux-Petel , Denis Werth

We consider the description of the clustering of halos for physically-motivated types of non-Gaussian initial conditions. In particular we include non-Gaussianity of the type arising from single field slow-roll, multi fields, curvaton…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Licia Verde , Sabino Matarrese

In this study, we explore the back reaction of phase transitions in the spectator sector on the inflaton field during slow-roll inflation. Due to the significant excursion of the inflaton field, these phase transitions are likely to occur…

High Energy Physics - Phenomenology · Physics 2024-11-20 Haipeng An , Qi Chen , Yuhang Li , Yuan Yin

We address whether possible scale-dependent deviations from gaussianity in the primordial density field that are consistent with the cosmic microwave background observations could explain the apparent excess of early cluster formation at…

Astrophysics · Physics 2009-11-10 H. Mathis , J. M. Diego , Joseph Silk

An observable stochastic background of gravitational waves is generated whenever primordial black holes are created in the early universe thanks to a small-scale enhancement of the curvature perturbation. We calculate the anisotropies and…

Cosmology and Nongalactic Astrophysics · Physics 2020-03-10 N. Bartolo , D. Bertacca , V. De Luca , G. Franciolini , S. Matarrese , M. Peloso , A. Ricciardone , A. Riotto , G. Tasinato

We investigate primordial tensor non-Gaussianity in single field inflation, during a phase of non-attractor evolution when the spectrum of primordial tensor modes can be enhanced to a level detectable at interferometer scales. Making use of…

High Energy Physics - Theory · Physics 2019-09-25 Ogan Ozsoy , Maria Mylova , Susha Parameswaran , Cari Powell , Gianmassimo Tasinato , Ivonne Zavala

Primordial non-Gaussianity, in particular the coupling of modes with widely different wavelengths, can have a strong impact on the large-scale clustering of tracers through a scale-dependent bias with respect to matter. We demonstrate that…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-26 Fabian Schmidt

We computed the power spectrum of weak cosmic shear in models with non-Gaussian primordial density fluctuations. Cosmological initial conditions deviating from Gaussianity have recently attracted much attention in the literature, especially…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 C. Fedeli , L. Moscardini

The bispectrum, the three-point function of density fluctuations in Fourier space, is the lowest order statistic that carries information about the spatial coherence of large-scale structures. For Gaussian initial conditions, when the…

It has been recently established that, if the nonlinear relationship between the overdensity perturbations and the curvature perturbations are taken into account, non-Gaussianity is introduced in the overdensity statistics which alters the…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-05 Rafid Mahbub