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Related papers: Constant-Roll Inflation

200 papers

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

We study the seemingly duality between large and small $\eta_H$ for the constant-roll inflation with the second slow-roll parameter $\eta_H$ being a constant. In the previous studies, only the constant-roll inflationary models with small…

General Relativity and Quantum Cosmology · Physics 2019-11-01 Qing Gao , Yungui Gong , Zhu Yi

In this paper we show that the dynamics associated with slow-roll models of inflation can be investigated through a method called deformation procedure. Using the latter, we explicitly derive an expression linking two slow-roll inflationary…

General Relativity and Quantum Cosmology · Physics 2015-03-19 Jamilton Rodrigues , Marcos Souza

The aim of this paper is to provide a more precise description of the paradigm of corpuscular slow-roll inflation, which was previously introduced by Casadio et al. in [1]. Specifically, we start by expanding the Starobinsky theory on a…

General Relativity and Quantum Cosmology · Physics 2019-09-04 Andrea Giugno , Andrea Giusti

It was pointed out previously~\cite{Kinney:2014jya} that a sufficiently negative running of the spectral index of curvature perturbations from (ordinary i.e. cold) inflation is able to prevent eternal inflation from ever occurring. Here, we…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-30 Gabriele Montefalcone , Rudnei O. Ramos , Gustavo S. Vicente , Katherine Freese

Constant-roll warm inflation is introduced in this work. A novel approach to finding an exact solution for Friedman equations coupled to scalar field equation of motion is presented for cold inflation and is extended to warm inflation with…

General Relativity and Quantum Cosmology · Physics 2020-07-17 Vahid Kamali , Michał Artymowski , Mohammad Reza Setare

Inflation is the currently accepted paradigm for the beginnings of the Universe. To explain the observed almost scale invariant spectrum of density perturbations with only a slight spectral tilt, inflation must have been "slow roll", that…

High Energy Physics - Theory · Physics 2021-01-07 Hao Geng

We propose a class of single-field, slow-roll inflation models in which a typical number of $e$-folds can be extremely large. The key point is to introduce a very shallow local minimum near the top of the potential in a hilltop inflation…

High Energy Physics - Phenomenology · Physics 2019-12-16 Naoya Kitajima , Yuichiro Tada , Fuminobu Takahashi

In this paper, we study a constant-roll inflationary model in the presence of a noncommutative parameter with a homogeneous scalar field minimally coupled to gravity. The specific noncommutative inflation conditions proposed new…

High Energy Physics - Theory · Physics 2023-02-14 J. Sadeghi , S. Noori Gashti

These lecture notes are based on those presented at the Theoretical Aspects of Astroparticle Physics, Cosmology and Gravitation School at the Galileo Galilee Institute in Florence in 2021, https://agenda.infn.it/event/24368/. They aim to…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-13 Christian T. Byrnes , Philippa S. Cole

We consider the impact of quantum diffusion on inflationary dynamics during an ultra-slow-roll phase, which can be of particular significance for the formation of primordial black holes. We show, by means of a fully analytical approach,…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-02 Guillermo Ballesteros , Julián Rey , Marco Taoso , Alfredo Urbano

We develop in this thesis the principles governing the production of our universe's primordial inhomogeneities during its early phase of inflation. As a guiding thread we ask what physics during inflation can lead to perturbations so large…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-18 Samuel Passaglia

Based on generalized holographic formalism, we establish a holographic realization of constant roll inflation during the early universe, where the corresponding cut-off depends on the Hubble parameter and its derivatives (up to the second…

General Relativity and Quantum Cosmology · Physics 2023-05-31 Shin'ichi Nojiri , Sergei D. Odintsov , Tanmoy Paul

We extend the Cecotti-Kallosh model of Starobinsky inflation in supergravity by adding a holomorphic function to the superpotential in order to generate a large peak in the power spectrum of scalar (curvature) perturbations. In our…

High Energy Physics - Theory · Physics 2023-02-06 Shuntaro Aoki , Ryotaro Ishikawa , Sergei V. Ketov

Ultra-slow-roll (USR) inflation is a new mode of inflation which corresponds to the occasions when the inflaton field must traverse an extremely flat part of the scalar potential, when the usual slow-roll (SR) fails. We investigate USR and…

High Energy Physics - Phenomenology · Physics 2017-12-06 Konstantinos Dimopoulos

Nonminimal coupling of the inflaton field to the Ricci curvature of spacetime is generally unavoidable, and the paradigm of inflation should be generalized by including the corresponding term in the Lagrangian of the inflationary theory.…

High Energy Physics - Theory · Physics 2014-11-18 Valerio Faraoni

We consider the eternal inflation scenario of the slow-roll/chaotic type with the additional element of an objective collapse of the wave function. The incorporation of this new agent to the traditional inflationary setting might represent…

General Relativity and Quantum Cosmology · Physics 2017-10-27 Gabriel Leon

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…

General Relativity and Quantum Cosmology · Physics 2021-04-05 Julien Grain , Vincent Vennin

Since the advent of inflation, several theorems have been proven suggesting that although inflation can (and generically does) continue eternally into the future, it cannot be extended eternally into the past to create a ``steady-state''…

Astrophysics · Physics 2009-11-07 Anthony Aguirre , Steven Gratton

By extending the potential, we propose a mechanism for the end of the constant-roll inflation and the subsequent reheating phase in the FLRW space-time. Based on astrophysical data, we estimate the Universe reheating temperature.

General Relativity and Quantum Cosmology · Physics 2020-01-22 H. Mohseni Sadjadi , V. Anari