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Related papers: Brane Constant-roll Inflation

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The meaning of the inflationary slow-roll approximation is formalised. Comparisons are made between an approach based on the Hamilton-Jacobi equations, governing the evolution of the Hubble parameter, and the usual scenario based on the…

Astrophysics · Physics 2009-10-22 Andrew R. Liddle , Paul Parsons , John D. Barrow

In the context of an inflationary Randall-Sundrum Type II braneworld (RS2) we calculate spectral indices and amplitudes of cosmological scalar and tensor perturbations, up to second order in slow-roll parameters. Under very simple…

High Energy Physics - Phenomenology · Physics 2009-11-10 Gianluca Calcagni

We study the slow-roll regime of two field inflation, in which the two fields are also coupled through their kinetic terms. Such Lagrangians are motivated by particle physics and by scalar-tensor theories studied in the Einstein frame. We…

Astrophysics · Physics 2009-11-11 Fabrizio Di Marco , Fabio Finelli

In this paper, warm inflationary models on a brane scenario are studied. Here we consider slow-roll inflation and high-dissipation regime in a high-energy scenario. General conditions required for these models to be realizable are derived.…

Astrophysics · Physics 2008-11-26 M. Antonella Cid , Sergio del Campo , Ramon Herrera

We study constant roll inflation systematically. This is a regime, in which the slow roll approximation can be violated. It has long been thought that this approximation is necessary for agreement with observations. However, recently it was…

High Energy Physics - Theory · Physics 2018-02-21 Lilia Anguelova , Peter Suranyi , L. C. Rohana Wijewardhana

We examine the dynamics of inflation driven by multiple, interacting scalar fields and derive a multi field version of the Hubble slow roll expansion. We show that the properties of this expansion naturally generalize those of the single…

Astrophysics · Physics 2013-05-29 Richard Easther , John T Giblin

Upper bounds on the energy scale at the end of inflation in the Randall-Sundrum type II braneworld scenario are derived. The analysis is made exact by introducing new parameters that represent extensions of the Hubble flow parameters. Only…

Astrophysics · Physics 2009-11-07 Rachael M. Hawkins , James E. Lidsey

In this article we study a constant-roll inflationary model in the context of brane-world cosmology caused by a quintessence scalar field for warm inflation with a constant dissipative parameter Q =$\Gamma$/3H. We determine the analytical…

General Relativity and Quantum Cosmology · Physics 2022-01-11 Mohammad Reza Setare , Arvin Ravanpak , Karam Bahari , Golnaz Farpour Fadakar

The beta function formalism is being used to study the constant-roll inflation in the k-essence model. Assuming the second slow-roll parameter as a constant leads to a first-order differential equation for $\beta$-function which is much…

General Relativity and Quantum Cosmology · Physics 2020-05-12 Abolhassan Mohammadi , Tayeb Golanbari , Khaled Saaidi

A study of the slow-roll inflation for an exponential potential in the frame of the scalar-tensor theory is performed, where non-minimal kinetic coupling to curvature and non-minimal coupling of the scalar field to the Gauss-Bonnet…

High Energy Physics - Theory · Physics 2019-09-24 L. N. Granda , D. F. Jimenez

If a coupling between the inflaton and the Gauss-Bonnet term is introduced, many models of inflation that were ruled out by the most recent Planck data can be made viable again. The predictions for the scalar spectral index and…

General Relativity and Quantum Cosmology · Physics 2025-04-22 Kamil Mudrunka , Kazunori Nakayama

In this work, we study a constant-roll inflationary model in the Palatini formalism using modified gravity. Here our action consists a non-minimal coupling of a scalar field $\phi$ with Ricci scalar $R$ in a general form of $f(R,\phi)$.…

General Relativity and Quantum Cosmology · Physics 2023-04-19 Sukanta Panda , Arun Rana , Rahul Thakur

We show that a corpuscular description of gravity can lead to an inflationary scenario similar to Starobinsky's model without requiring the introduction of the inflaton field. All relevant properties are determined by the number of…

General Relativity and Quantum Cosmology · Physics 2018-10-30 Roberto Casadio , Andrea Giugno , Andrea Giusti

Using Hamilton-Jacobi formalism, The scenario of warm inflation with viscous pressure is considered. The formalism gives a way of computing the slow-rolling parameters without extra approximation, and it is well-known as a powerful method…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-17 L. Akhtari , A. Mohammadi , K. Sayar , Kh. Saaidi

We study the slow-roll inflationary dynamics in a self-gravitating induced gravity braneworld model with bulk cosmological constant. For E \gg M_{5}^{3}/M^{2}_{2} we find important corrections to the four-dimensional Friedmann equation…

General Relativity and Quantum Cosmology · Physics 2009-11-10 E. Papantonopoulos , V. Zamarias

This study concerns the consistency of the tachyon warm inflationary models. A linear stability analysis is performed to find the slow-roll conditions, characterized by the potential slow-roll (PSR) parameters, for the existence of a…

General Relativity and Quantum Cosmology · Physics 2014-02-25 Xiao-Min Zhang , Jian-Yang Zhu

We study constant-roll inflation using the $\beta$-function formalism. We show that the constant rate of the inflaton roll is translated into a first order differential equation for the $\beta$-function which can be solved easily. The…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-09 F. Cicciarella , J. Mabillard , M. Pieroni

We consider models of a scalar field coupled to quadratic $R\!+\!R^2$ gravity in the framework of the Palatini formulation. The resulting Einstein-frame generalized $k$-inflation effective theory is analyzed assuming that the constant-roll…

General Relativity and Quantum Cosmology · Physics 2020-04-29 Ignatios Antoniadis , Angelos Lykkas , Kyriakos Tamvakis

According to a Barrow's solution for the scale factor of the universe, the main properties of the tachyon inflation model in the framework of RSII braneworld are studied. Within this framework the basic slow-roll parameters are calculated…

General Relativity and Quantum Cosmology · Physics 2017-08-02 Vahid Kamali , Elahe Navaee Nik

The slow-roll inflation paradigm can be systematically generalized within the framework of non-standard entropy formalisms, giving rise to a broad class of inflationary models that deviate from the conventional Bekenstein--Hawking case. We…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-26 H R M Zarandi , Esmaiel Ebrahimi , Yo Toda