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Related papers: (Pre)-Inflationary Dynamics with Starobinsky Poten…

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We give a brief review of the basic principles of inflationary theory and discuss the present status of the simplest inflationary models that can describe Planck/BICEP/Keck observational data by choice of a single model parameter. In…

High Energy Physics - Theory · Physics 2025-10-28 Renata Kallosh , Andrei Linde

An investigation is undertaken into the properties and effects of a preinflationary era during at least part of which semiclassical gravity was valid. It is argued that if the Universe (or our part of it) was approximately homogeneous and…

General Relativity and Quantum Cosmology · Physics 2021-05-25 Paul R. Anderson , Eric D. Carlson , Taylor M. Ordines , Bradley Hicks

In this work we use the Loop Quantum Cosmology modified scalar-tensor reconstruction techniques in order to investigate how bouncing and inflationary cosmologies can be realized. With regard to the inflationary cosmologies, we shall be…

General Relativity and Quantum Cosmology · Physics 2018-04-18 K. Kleidis , V. K. Oikonomou

At the level of heuristic effective dynamics, we investigate the cosmological inflation with holonomy corrections of loop quantum cosmology (LQC) in the $k=0$ Friedmann-Robertson-Walker model with a single inflaton field subject to a simple…

General Relativity and Quantum Cosmology · Physics 2010-04-29 Dah-Wei Chiou , Kai Liu

Scalar fields with an energy density dominated by its kinetic part may have played a relevant role in the very early stages of the Universe. Compared to the standard inflationary paradigm, they may lead to modifications in observable…

General Relativity and Quantum Cosmology · Physics 2021-11-23 Beatriz Elizaga Navascués , Rafael Jiménez-Llamas , Guillermo A. Mena Marugán

We consider the description of cosmological dynamics from the onset of inflation by a perfect fluid whose parameters must be consistent with the strength of the enhanced quantum loop effects that can arise during inflation. The source of…

General Relativity and Quantum Cosmology · Physics 2010-04-14 N. C. Tsamis , R. P. Woodard

We consider the dynamics of a spatially flat universe dominated by a self-interacting nonminimally coupled scalar field. The structure of the phase space and complete phase portraits for the conformal coupling case are given. It is shown…

General Relativity and Quantum Cosmology · Physics 2007-05-23 A. Saa , E. Gunzig , L. Brenig , V. Faraoni , T. M. Rocha Filho , A. Figueiredo

This review article aims at presenting the theory of inflation. We first describe the background spacetime behavior during the slow-roll phase and analyze how inflation ends and the Universe reheats. Then, we present the theory of…

High Energy Physics - Theory · Physics 2009-11-10 Jerome Martin

The most current observational data corroborate the Starobinsky model as one of the strongest candidates in the description of an inflationary regime. Motivated by such success, extensions of the Starobinsky model have been increasingly…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-14 G. Rodrigues-da-Silva , J. Bezerra-Sobrinho , L. G. Medeiros

In this paper we investigate the asymptotic dynamics of inflationary cosmological models that are based in scalar-tensor theories of gravity. Our main aim is to explore the global structure of the phase space in the framework of…

General Relativity and Quantum Cosmology · Physics 2020-05-20 Israel Quiros , Tame Gonzalez , Roberto De Arcia , Ricardo García-Salcedo , Ulises Nucamendi , Joel F. Saavedra

The dynamics of a preinflacionary phase of the universe, and its exit to inflation, is discussed. This phase is modeled by a closed Friedmann-Robertson-Walker geometry, the matter content of which is radiation plus a scalar field minimally…

General Relativity and Quantum Cosmology · Physics 2009-10-31 G. A. Monerat , H. P. de Oliveira , Ivano D. Soares

We show that the quantum dynamics of a real scalar field for a large class of potentials in the symmetric Gaussian state, where the nonperturbative quantum contributions are taken into account, can be described equivalently by a…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Dongsu Bak , Sang Pyo Kim , Sung Ku Kim , Kwang-Sup Soh , Jae Hyung Yee

In this paper, we consider a nonminimal coupling model between gravity and nonlinear electrodynamics with cosmological constant. This cosmological model is designed to account for both the inflationary epoch of the early universe and the…

General Relativity and Quantum Cosmology · Physics 2024-10-10 Chilwatun Nasiroh , Ramy F. Izzah , Fiki T. Akbar , Bobby E. Gunara

This paper consider an universe dominated by baryonic matter, radiation and a nonminimally coupled massive scalar field under the action of a symmetry breaking potential. Inflation occurs naturally with appropriated slow-roll values. The…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-02 S. H. Pereira

This paper investigates a scale-invariant inflationary model characterized by a scalar field non-minimally coupled to gravity and a curvature term quadratic in the Ricci scalar. The model's dynamic is analyzed using a full numerical…

High Energy Physics - Theory · Physics 2024-10-10 Mariaveronica De Angelis , Chiara Cecchini , Massimiliano Rinaldi

Inflation in cosmology is a specific stage preceding the Big Bang, aimed at solving both old background problems and new perturbation issues. Single-field inflation is a candidate to illustrate the picture of the initial universe, and…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-21 Guanqiao Liu

A finite duration of cosmic inflation can result in features $\mathcal{P}_{\mathcal{R}}(k) = |\alpha_k-\beta_k\,\mathrm{e}^{\mathrm{i}\delta_k}|^2 \,\mathcal{P}_{\mathcal{R}}^{(0)}(k)$ in the primordial power spectrum that carry information…

General Relativity and Quantum Cosmology · Physics 2025-03-17 Eugenio Bianchi , Mauricio Gamonal

In this paper we find a solution for a quasi-isotropic inflationary Universe which allows to introduce in the problem a certain degree of inhomogeneity. We consider a model which generalize the (flat) FRW one by introducing a first order…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Giovanni Paolo Imponente , Giovanni Montani

Inflationary models that contain a transient ultra-slow-roll phase can exhibit strong non-perturbative dynamics, making the usual perturbative treatment of cosmological fluctuations incomplete. In such regimes, quantum diffusion and the…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-29 Xiao-Quan Ye , Shao-Jiang Wang

In this brief review we introduce the methods of quantum field theory out of equilibrium and study the non-equilibrium aspects of phase transitions. Specifically we critically study the picture of the ``slow-roll'' phase transition in the…

High Energy Physics - Theory · Physics 2009-09-25 D. Boyanovsky , H. J. de Vega , R. Holman