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Related papers: Non-gaussianity in fluctuations from warm inflatio…

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We numerically investigate reheating after quadratic inflation with up to 65 fields, focusing on the production of non-Gaussianity. We consider several sets of initial conditions, masses and decay rates. As expected we find that the…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-05 Pedro Carrilho , David Mulryne , John Ronayne

We compute the spectrum of cosmological perturbations in a scenario in which inflation is driven by radiation in a non-commutative space-time. In this scenario, the non-commutativity of space and time leads to a modified dispersion relation…

High Energy Physics - Theory · Physics 2010-10-27 Seoktae Koh , Robert H. Brandenberger

We calculate the contribution of the fluctuations with the thermal origin to the inflationary nonGaussianity. We find that even a small component of radiation can lead to a large nonGaussianity. We show that this thermal nonGaussianity…

High Energy Physics - Theory · Physics 2009-12-15 Bin Chen , Yi Wang , Wei Xue

We investigate the cosmological perturbation theory and calculate the perturbation spectra in the warm $k$-inflation. Unlike the scalar perturbations of $k$-inflation in the cold inflationary scenario, entropy perturbations should be…

General Relativity and Quantum Cosmology · Physics 2018-04-18 Zhi-Peng Peng , Jia-Ning Yu , Xiao-Min Zhang , Jian-Yang Zhu

Recent study [1] has suggested that warm inflation may be realized with a minimal extension of the Standard Model by a single scalar inflaton field with an axion-like coupling to gluons. Motivated by this framework, we investigate the…

High Energy Physics - Phenomenology · Physics 2026-03-18 Quan Chen , Siyu Jiang , Dayun Qiu , Peilin Chen , Fa Peng Huang

We study the evolution of quantum fluctuations of gravity around an inflationary solution in renormalizable quantum gravity, in which the initial scalar-fluctuation dominance is shown by the background-free nature expressed by a special…

High Energy Physics - Theory · Physics 2024-01-19 Ken-ji Hamada

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

We calculate the scale dependence of the bispectrum and trispectrum in (quasi) local models of non-Gaussian primordial density perturbations, and characterize this scale dependence in terms of new observable parameters. They can help to…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-12 Christian T. Byrnes , Mischa Gerstenlauer , Sami Nurmi , Gianmassimo Tasinato , David Wands

Inflationary scenarios in string theory often involve a large number of light scalar fields, whose presence can enrich the post-inflationary evolution of primordial fluctuations generated during the inflationary epoch. We provide a simple…

High Energy Physics - Theory · Physics 2010-08-18 C. P. Burgess , M. Cicoli , M. Gomez-Reino , F. Quevedo , G. Tasinato , I. Zavala

We discuss how primordial non-Gaussianity of the curvature perturbation helps to constrain models of the early universe. Observations are consistent with Gaussian initial conditions, compatible with the predictions of the simplest models of…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-26 Christian T. Byrnes

This article examines how breaking a Lorentz-invariant description of nature at tiny space-time intervals would affect the non-Gaussian character of the pattern of primordial perturbations left by inflation. We specifically study a set of…

High Energy Physics - Phenomenology · Physics 2009-09-01 Hael Collins , R. Holman

This paper presents and investigates non-Gaussian perturbations for the warm k-inflation model that is driven by pure kinetic energy. The two complementary components of the overall non-Gaussianity are the three-point and four-point…

General Relativity and Quantum Cosmology · Physics 2023-06-28 Chao-Qun Shen , Xiao-Min Zhang , Zhi-Peng Peng , He Liu , Xi-Bin Li , Peng-Cheng Chu

We present a numerical integration of the cosmological scalar perturbation equations in warm inflation. The initial conditions are provided by a discussion of the thermal fluctuations of an inflaton field and thermal radiation using a…

Astrophysics · Physics 2009-11-07 Lisa M. H. Hall , Ian G. Moss , Arjun Berera

We investigate non-Gaussianity in the modulated reheating scenario where fluctuations of the decay rate of the inflaton generate adiabatic perturbations, paying particular attention to the non-linearity parameters $f_{\rm NL}, \tau_{\rm…

Astrophysics · Physics 2008-11-26 Kazuhide Ichikawa , Teruaki Suyama , Tomo Takahashi , Masahide Yamaguchi

Warm inflation dynamics is fundamentally based on a system-reservoir configuration in which the dynamics is dictated by a fluctuation-dissipation relation. Recent work by Cerioni et. al. (arXiv:0804.0163) examined dissipative dynamics with…

Astrophysics · Physics 2008-05-15 Arjun Berera , Lisa M. H. Hall , Ian G. Moss , Hiranya V. Peiris

We calculate the spectrum of density fluctuations in models of inflation based on a weakly self-coupled scalar matter field minimally coupled to gravity, and specifically investigate the dependence of the predictions on modifications of the…

Astrophysics · Physics 2009-10-31 Robert H. Brandenberger , Jerome Martin

We study the possibility that particle production during inflation could source observable gravity waves on scales relevant for Cosmic Microwave Background experiments. A crucial constraint on such scenarios arises because particle…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Neil Barnaby , Jordan Moxon , Ryo Namba , Marco Peloso , Gary Shiu , Peng Zhou

We study the bispectrum of the primordial curvature perturbation on uniform-density hypersurfaces generated by a kind of the noncanonical warm inflation, wherein the inflation is provided by a noncanonical scalar inflaton field that is…

General Relativity and Quantum Cosmology · Physics 2015-04-09 Xiao-Min Zhang , Jian-Yang Zhu

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

In this paper, we investigate scalar-induced gravitational waves (GWs) generated in the post-inflationary universe to infer new limits on warm inflation. We specifically examine the evolution of primordial GWs by scalar perturbations…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-26 Rocco D'Agostino , Matteo Califano