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Related papers: Constraints on \alpha-attractor inflation and rehe…

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Cosmological $\alpha$-attractors are a compelling class of inflationary models. They lead to universal predictions for large-scale observables, broadly independent from the functional form of the inflaton potential. In this work we derive…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-21 Laura Iacconi , Matteo Fasiello , Jussi Väliviita , David Wands

In this paper, we discuss three modified single-field natural inflation models in detail, including Special generalized Natural Inflation model(SNI), Extended Natural Inflation model(ENI) and Natural Inflation inspired model(NII). We derive…

High Energy Physics - Phenomenology · Physics 2022-07-13 Hua Zhou , Qing Yu , Yu Pan , Ruiyu Zhou , Wei Cheng

We revisit the inflection point inflation with an extended discussion to large field values and consider the reheating effects on the inflationary predictions. Parametrizing the reheating dynamics in terms of the reheating temperature and…

High Energy Physics - Phenomenology · Physics 2016-06-22 Soo-Min Choi , Hyun Min Lee

We study observational viability of Natural Inflation with a tachyon field as inflaton. By obtaining the main perturbation parameters in this model, we perform a numerical analysis on the parameter space of the model and in confrontation…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-23 Narges Rashidi , Kourosh Nozari , Oyvind Gron

We study the impacts of reheating temperature on the inflationary predictions of the spectral index and tensor-to-scalar ratio. Assuming sinusoidal oscillations and that reheating process is very fast, the reheating temperature can be…

High Energy Physics - Phenomenology · Physics 2015-05-27 Jinn-Ouk Gong , Shi Pi , Godfrey Leung

We analyze in detail the perturbative decay of the inflaton oscillating about a generic form of its potential $V(\phi) = \phi^k$, taking into account the effects of non-instantaneous reheating. We show that evolution of the temperature as a…

High Energy Physics - Phenomenology · Physics 2021-04-14 Marcos A. G. Garcia , Kunio Kaneta , Yann Mambrini , Keith A. Olive

We investigate the impact of different choice of prior's range for the reheating epoch on cosmic inflation parameter inference in light of cosmic microwave background (CMB) anisotropy measurements from the {\em Planck} 2018 legacy release…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-30 Mario Ballardini

We show how observations of the perturbation spectra produced during inflation may be used to constrain the parameters of general scalar-tensor theories of gravity, which include both an inflaton and dilaton field. An interesting feature of…

General Relativity and Quantum Cosmology · Physics 2016-08-24 Juan Garcia-Bellido , David Wands

The scenario of the slow-roll inflation is studied in the frame of the scalar-tensor theory of gravity where the scalar field has a non-minimal coupling to the geometric part. After deriving the main dynamical and perturbation equations,…

General Relativity and Quantum Cosmology · Physics 2020-12-01 Abolhassan Mohammadi , Tayeb Golanbari , Jamil Enayati , Shahram Jalalzadeh , Khaled Saaidi

A scenario with two subsequent periods of inflationary expansion in the very early universe is examined. The model is based on a potential motivated by symmetries being found in field theory at high energy. For various parameter sets of the…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-13 Simon Schettler , Jurgen Schaffner-Bielich

We study two-field inflation derived from a single complex scalar field with a nonzero vacuum expectation value. The dynamics of inflation are governed by two parameters, the vacuum expectation value and the mass parameter of the phase…

High Energy Physics - Phenomenology · Physics 2025-12-18 Yoshihiko Abe , Toshimasa Ito , Koichi Yoshioka

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

Recently, a combined model of the primordial inflation and the present cosmic acceleration has been proposed in the context of f(R) gravity. This model is composed of the late-time acceleration term and an R2 term, which enables the model…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-23 Atsushi Nishizawa , Hayato Motohashi

We investigate the production of a spectator scalar dark matter field that is directly coupled to the inflaton during inflation and reheating. We consider two specific inflationary potentials, namely the Starobinsky and T-model of…

High Energy Physics - Phenomenology · Physics 2023-06-16 Marcos A. G. Garcia , Mathias Pierre , Sarunas Verner

We present a model of inflation where the inflaton is accommodated as a phantom field which exhibits an initial transient pole behavior and then decays into a quintessence field which is responsible for a radiation era. We must stress that…

General Relativity and Quantum Cosmology · Physics 2017-02-01 Martin G. Richarte , Gilberto M. Kremer

In the inflationary framework of cosmology the initial phase of rapid expansion has to be followed by a reheating stage, which is envisioned to end in a radiation dominated big bang. Key parameters that characterize this big bang state are…

High Energy Physics - Phenomenology · Physics 2018-10-29 Rolf Schimmrigk

In this paper we illustrate an interesting example of low scale inflation with an extremely large number of e-foldings. This realization can be implemented easily in hybrid inflation model where usually inflation ends via phase transition.…

High Energy Physics - Theory · Physics 2007-05-23 Anupam Mazumdar

We consider the effects of fragmentation on the post-inflationary epoch of reheating. In simple single field models of inflation, an inflaton condensate undergoes an oscillatory phase once inflationary expansion ends. The equation of state…

High Energy Physics - Phenomenology · Physics 2023-12-19 Marcos A. G. Garcia , Mathieu Gross , Yann Mambrini , Keith A. Olive , Mathias Pierre , Jong-Hyun Yoon

We investigate the dependence of the gravitational wave spectrum from quintessential inflation on the reheating process. We consider two extreme reheating processes. One is the gravitational reheating by particle creation in the expanding…

General Relativity and Quantum Cosmology · Physics 2009-10-09 Hiroyuki Tashiro , Takeshi Chiba , Misao Sasaki

We have studied the preheating phase for a class of plateau inflationary model considering the four-legs interaction term $(1/2)g^2\phi^2\chi^2$ between the inflaton $(\phi)$ and reheating field $(\chi)$. We specifically focus on the…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-16 Debaprasad Maity , Pankaj Saha