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相关论文: Revisiting non-Gaussianity from non-attractor infl…

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In the present paper, certain inflation models are shown to have large non-Gaussianity in special cases. Namely, finite length inflation models with an effective higher derivative interaction, in which slow-roll inflation is adopted as…

宇宙学与河外天体物理 · 物理学 2010-04-26 Shiro Hirai , Tomoyuki Takami

In this paper we mainly focus on the curvature perturbation generated at the end of multi-field inflation, such as the multi-brid inflation. Since the curvature perturbation is produced on the super-horizon scale, the bispectrum and…

高能物理 - 理论 · 物理学 2010-04-15 Qing-Guo Huang

We study the slow-roll single field inflation in the context of the consistent $D\to4$ Einstein-Gauss-Bonnet gravity that was recently proposed in \cite{Aoki:2020lig}. In addition to the standard attractor regime, we find a new attractor…

广义相对论与量子宇宙学 · 物理学 2021-05-03 Katsuki Aoki , Mohammad Ali Gorji , Shuntaro Mizuno , Shinji Mukohyama

We calculate the general solutions for a warm inflationary scenario with weak dissipation, reviewing the dissipative dynamics of the two-fluid system, and calculate the bispectrum of the gravitational field fluctuations generated in the…

天体物理学 · 物理学 2008-11-26 Sujata Gupta

There have been long debates about the initial condition of inflationary perturbations. In this work we explicitly show the decay of excited states during inflation via interactions. For this purpose, we note that the folded shape…

高能物理 - 理论 · 物理学 2016-08-03 Hongliang Jiang , Yi Wang

We present a class of models in which the primordial metric fluctuations do not necessarily obey Gaussian statistics. These models are realizations of mechanisms in which non-Gaussianity is first generated by a light scalar field and then…

天体物理学 · 物理学 2009-11-11 Francis Bernardeau , Tristan Brunier , Jean-Philippe Uzan

We consider primordial fluctuations in thermal inflation scenario. Since the thermal inflation drives about 10 $e$-folds after the standard inflation, the time of horizon-exit during inflation corresponding to the present observational…

高能物理 - 理论 · 物理学 2010-02-18 Masahiro Kawasaki , Tomo Takahashi , Shuichiro Yokoyama

DHOST inflation models where deviations from a pure de Sitter background are induced by an axion-like potential can lead to large non-Gaussianities. We investigate the nature of non-Gaussianities in these models and compare to the results…

宇宙学与河外天体物理 · 物理学 2024-10-31 Philippe Brax , Andrei Lazanu

We consider a variant of hybrid inflation where the waterfall phase transition happens during inflation. By adjusting the parameters associated with the mass of the waterfall field we arrange that the phase transition is not sharp so…

宇宙学与河外天体物理 · 物理学 2015-05-20 Ali Akbar Abolhasani , Hassan Firouzjahi , Mohammad Hossein Namjoo

These notes present a detailed introduction to Maldacena's calculation of the three-point function generated by the simplest class of inflationary models: those with a single inflaton field whose potential satisfies the slow-roll conditions…

宇宙学与河外天体物理 · 物理学 2014-06-02 Hael Collins

We show that modifications of Einstein gravity during inflation could leave potentially measurable imprints on cosmological observables in the form of non-Gaussian perturbations. This is due to the fact that these modifications appear in…

宇宙学与河外天体物理 · 物理学 2014-10-22 Nicola Bartolo , Dario Cannone , Raul Jimenez , Sabino Matarrese , Licia Verde

We present a detailed study of the generation of large primordial non-Gaussianities during the slow-roll (SR) to ultra-slow roll (USR) transitions in the framework of Galileon inflation. We found out that due to having sharp transitions in…

宇宙学与河外天体物理 · 物理学 2024-01-11 Sayantan Choudhury , Ahaskar Karde , Sudhakar Panda , M. Sami

We provide a derivation from first principles of the primordial bispectrum of scalar perturbations produced during inflation driven by a canonically normalized scalar field whose potential exhibits small sinusoidal modulations. A potential…

高能物理 - 理论 · 物理学 2015-05-18 Raphael Flauger , Enrico Pajer

Curvature perturbations generated after the end of inflation are estimated for a generic multi-field inflationary potential. The curvature perturbations are generated by conversion of inflationary isocurvature perturbations, similar to…

天体物理学 · 物理学 2007-05-23 Andrei Gruzinov

Tensor non-Gaussianity represents an important future probe of the physics of inflation. Inspired by recent works, we elaborate further on the possibility of significant primordial tensor non-Gaussianities sourced by extra fields during…

宇宙学与河外天体物理 · 物理学 2019-02-20 Emanuela Dimastrogiovanni , Matteo Fasiello , Gianmassimo Tasinato , David Wands

An inflationary model can be constrained by non-gaussian statistics as a parameter in the LSS (Large Scale Structure) distribution, and in the radiation of CMB (Cosmic Microwave Background) fluctuating temperature. Data on the CMB from…

广义相对论与量子宇宙学 · 物理学 2025-12-11 A. Agung , U. Sambiri , G. Hikmawan , F. P. Zen

The slow-roll approximation to inflation is ultimately justified by the presence of inflationary attractors for the orbits of the solutions of the dynamical equations in phase space. There are many indications that the inflaton field…

广义相对论与量子宇宙学 · 物理学 2011-08-11 Valerio Faraoni

Many alternatives to canonical slow-roll inflation have been proposed over the years, one of the main motivations being to have a model, capable of generating observable values of non-Gaussianity. In this work, we (re-)explore the physical…

高能物理 - 理论 · 物理学 2016-07-06 David Pirtskhalava , Luca Santoni , Enrico Trincherini

We study the non-Gaussian features in single-field slow-roll inflationary scenario where inflation is preceded by a radiation era. In such a scenario both bispectrum and trispectrum non-Gaussianities are enhanced. Interestingly, the…

宇宙学与河外天体物理 · 物理学 2014-03-11 Suratna Das

An appealing feature of inflationary cosmology is the presence of a phase-space attractor, "slow roll", which washes out the dependence on initial field velocities. We investigate the robustness of this property under backreaction from…

广义相对论与量子宇宙学 · 物理学 2021-04-05 Julien Grain , Vincent Vennin