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Related papers: The running curvaton

200 papers

In this paper, we study a curvaton model where the curvaton is acted by Galileon field. We calculate the power spectrum of fluctuation of G-curvaton during inflation and discuss how it converts to the curvature perturbation after the end of…

High Energy Physics - Phenomenology · Physics 2015-05-30 Hua Wang , Taotao Qiu , Yun-Song Piao

We compute the power spectrum of curvature perturbations in stochastic inflation. This combines the distribution of first crossing times through the end-of-inflation surface, which has been previously studied, with the distribution of the…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-27 Kenta Ando , Vincent Vennin

We investigate the scale-dependence, or the runnings, of linear and second order density perturbations generated in various curvaton scenarios. We argue that the second order perturbations, i.e. non-Gaussianity, can strongly depend on the…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-12 Takeshi Kobayashi , Tomo Takahashi

We present an explicit cosmological model where inflation and dark energy both could arise from the dynamics of the same scalar field. We present our discussion in the framework where the inflaton field $\phi$ attains a nearly constant…

High Energy Physics - Theory · Physics 2008-11-26 Ishwaree P. Neupane

In non-oscillatory (NO) inflationary models, the reheating mechanism was usually based on gravitational particle production or the mechanism of instant preheating. In this paper we introduce the curvaton mechanism into NO models to reheat…

High Energy Physics - Phenomenology · Physics 2009-11-07 Bo Feng , Mingzhe Li

We conduct a thorough study of the comoving curvature perturbation $\mathcal{R}$ in single-field inflation with two stages, represented by a piecewise quadratic potential, where both the first and second derivatives are allowed to be…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-23 Xinpeng Wang , Xiao-Han Ma , Misao Sasaki

Inflationary cosmology proposes that the early Universe undergoes accelerated expansion, driven, in simple scenarios, by a single scalar field, or inflaton. The form of the inflaton potential determines the initial spectra of density…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-21 Richard Easther , Benedict Bahr-Kalus , David Parkinson

The parametric resonance responsible for preheating after inflation will end when self-interactions of the resonating field and interactions of this field with secondary degrees of freedom become important. In many cases, the effect may be…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Rose Lerner , Anders Tranberg

Whereas preheating after chaotic and hybrid inflation models has been abundantly studied in the literature, preheating in small field inflation models, where the curvature of the inflaton potential is negative during inflation, remains less…

High Energy Physics - Theory · Physics 2015-03-17 Philippe Brax , Jean-Francois Dufaux , Sophie Mariadassou

We present a model where the inflaton field behaves like quintessence at late times, generating the present phase of accelerated expansion. This is achieved within the framework of warm inflation, in particular the Warm Little Inflaton…

High Energy Physics - Phenomenology · Physics 2019-10-23 João G. Rosa , Luís B. Ventura

We study single-field inflationary models with steep step-like features in the potential that lead to the temporary violation of the slow-roll conditions during the evolution of the inflaton. These features enhance the power spectrum of the…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-18 I. Dalianis , G. P. Kodaxis , I. D. Stamou , N. Tetradis , A. Tsigkas-Kouvelis

We discuss features of the inflaton potential that can lead to a strong enhancement of the power spectrum of curvature perturbations. We show that a steep decrease of the potential induces an enhancement of the spectrum by several orders of…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-14 K. Kefala , G. P. Kodaxis , I. D. Stamou , N. Tetradis

We extend the formalism to calculate non-Gaussianity of primordial curvature perturbations produced by preheating in the presence of a light scalar field. The calculation is carried out in the separate universe approximation using the…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-31 Pulkit S. Ghoderao , Arttu Rajantie

We propose an inflationary scenario where the inflaton field is non-minimally coupled to spacetime curvature and inflation is driven by a vacuum energy symmetry breaking potential without specifying \emph{a priori} whether the inflaton…

General Relativity and Quantum Cosmology · Physics 2024-06-04 Alessio Belfiglio , Youri Carloni , Orlando Luongo

We study non-Gaussianity of density perturbations generated by an axionic curvaton, focusing on the case that the curvaton sits near the hilltop of the potential during inflation. Such hilltop curvatons can generate a red-tilted density…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-15 Masahiro Kawasaki , Takeshi Kobayashi , Fuminobu Takahashi

We propose a curvaton model in which the initial condition of the curvaton oscillation is determined by its attractor behavior during inflation. Assuming a chaotic inflation model, we find that the initial condition determined by the…

High Energy Physics - Phenomenology · Physics 2013-03-27 Keisuke Harigaya , Masahiro Ibe , Masahiro Kawasaki , Tsutomu T. Yanagida

We revise the Non-Gaussianity of canonical curvaton scenario with a generalized $\delta N$ formalism, in which it could handle the generic potentials. In various curvaton models, the energy density is dominant in different period including…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-18 Lei-Hua Liu , Bin Liang , Ya-Chen Zhou , Xiao-Dan Liu , Wu-Long Xu , Ai-Chen Li

The possibility that primordial black holes constitute a fraction of dark matter motivates a detailed study of possible mechanisms for their production. Black holes can form by the collapse of primordial curvature fluctuations, if the…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-06 Ogan Özsoy , Gianmassimo Tasinato

It is usually supposed that inflation is of the slow-roll variety, and that the inflaton generates the primordial curvature perturbation. According to the curvaton hypothesis, inflation need not be slow-roll, and if it is the inflaton…

High Energy Physics - Phenomenology · Physics 2009-07-09 Konstantinos Dimopoulos , David H. Lyth

We consider inflaton couplings to MSSM flat directions and the thermalization of the inflaton decay products, taking into account gauge symmetry breaking due to flat direction condensates. We then search for a suitable curvaton candidate…

High Energy Physics - Phenomenology · Physics 2009-11-11 Rouzbeh Allahverdi , Kari Enqvist , Asko Jokinen , Anupam Mazumdar