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Related papers: Quintessential Inflation from Lorentzian Slow Roll

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We study quintessential inflation using a generalized exponential potential $V(\phi)\propto exp(-\lambda \phi^n/Mpl^n), n>1$, the model admits slow-roll inflation at early times and leads to close-to-scaling behaviour in the post…

General Relativity and Quantum Cosmology · Physics 2017-06-21 Chao-Qiang Geng , Chung-Chi Lee , M. Sami , Emmanuel N. Saridakis , Alexei A. Starobinsky

In this paper we study a class of quintessential Einstein Gauss-Bonnet models, focusing on their early and late-time phenomenology. With regard to the early-time phenomenology, we formalize the slow-roll evolution of these models and we…

General Relativity and Quantum Cosmology · Physics 2019-10-23 K. Kleidis , V. K. Oikonomou

Recently Peebles and Vilenkin proposed and quantitatively analyzed the fascinating idea that a substantial fraction of the present cosmic energy density could reside in the vacuum potential energy of the scalar field responsible for…

Astrophysics · Physics 2007-05-23 Carlo Baccigalupi , Francesca Perrotta

We comment on the choice of the quintessence potential, examining the slow-roll approximation in a minimally coupled theory of gravity. We make some considerations on the potential behaviors, the related \gamma parameter, and their…

Astrophysics · Physics 2008-11-26 M. Capone , C. Rubano , P. Scudellaro

We present an explicit observationally acceptable model for evolution from inflation to the present epoch under the assumption that the entropy and matter of the familiar universe are from gravitational particle production at the end of…

Astrophysics · Physics 2016-08-25 P. J. E. Peebles , A. Vilenkin

The behavior of the quintessence field is studied during inflation. In order to have a satisfactory model of dark energy, the quintessence field value today should be as insensible to the initial conditions as possible. Usually, only the…

Astrophysics · Physics 2008-11-26 Jerome Martin , Marcello A. Musso

We investigate a compelling model of quintessential inflation in the context of $\alpha$-attractors, which naturally result in a scalar potential featuring two flat regions, the inflationary plateau and the quintessential tail. The…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-28 Konstantinos Dimopoulos , Leonora Donaldson Wood , Charlotte Owen

A simple model of quintessential inflation with the modified exponential potential $e^{-\alpha \phi} [A+(\phi-\phi_0)^2]$ is analyzed in the braneworld context. Considering reheating via instant preheating, we conclude that the model…

Astrophysics · Physics 2008-09-11 M. C. Bento , R. Gonzalez Felipe , N. M. C. Santos

In a recent work, a particular class of $f(T)$ gravity, where $T$ is the teleparallel torsion scalar, has been derived. This class has been identified by flat-like universe (FLU) assumptions \cite{HN15}. The model is consistent with the…

General Relativity and Quantum Cosmology · Physics 2016-10-19 W. El Hanafy , G. G. L. Nashed

We study in detail a new model of quintessential inflation where the inflaton field is coupled to the Gauss-Bonnet term. This coupling ensures that the variation of the field is kept sub-Planckian, which avoids the 5th force problem as well…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-24 Carsten van de Bruck , Konstantinos Dimopoulos , Chris Longden , Charlotte Owen

It has been widely claimed that inflation is generically eternal to the future, even in models where the inflaton potential monotonically increases away from its minimum. The idea is that quantum fluctuations allow the field to jump uphill,…

High Energy Physics - Theory · Physics 2009-11-11 Steven Gratton , Neil Turok

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

Making observable predictions for cosmic inflation requires determining when the wavenumbers of astrophysical interest today exited the Hubble radius during the inflationary epoch. These instants are commonly evaluated using the slow-roll…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-17 Pierre Auclair , Baptiste Blachier , Christophe Ringeval

We construct a model of quintessential inflation in Palatini $R^2$ gravity employing a scalar field with a simple exponential potential and coupled to gravity with a running non-minimal coupling. At early times, the field acts as the…

General Relativity and Quantum Cosmology · Physics 2022-11-03 Konstantinos Dimopoulos , Alexandros Karam , Samuel Sánchez López , Eemeli Tomberg

We present a unified framework that simultaneously addresses the dynamics of early-time cosmic inflation and late-time cosmic acceleration within the context of a single scalar field non-minimally coupled to gravity. By employing an…

General Relativity and Quantum Cosmology · Physics 2025-10-27 Seong Chan Park

Quintessential inflation provides a unified description of inflation and dark energy in terms of a single scalar degree of freedom, the cosmon. We present here a comprehensive overview of this appealing paradigm, highlighting its key…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-04 Dario Bettoni , Javier Rubio

The equations for quintessential $\alpha$-attractor inflation with a single scalar field, radiation and matter in a spatially flat FLRW spacetime are recast into a regular dynamical system on a compact state space. This enables a complete…

General Relativity and Quantum Cosmology · Physics 2024-02-08 Artur Alho , Claes Uggla

Inflationary models of the early universe provide a natural mechanism for the formation of large scale structure. This success brings to forefront the question of naturalness: Does a sufficiently long slow roll inflation occur generically…

General Relativity and Quantum Cosmology · Physics 2015-05-27 Abhay Ashtekar , David Sloan

Dark energy can be characterized by a canonical scalar field, known as quintessence. Quintessence allows for a dynamical equation of state $-1 \le \omega \le -\frac{1}{3}$. A previous study by Oikonomou and Chatzarakis have shown that a…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-11 Sreerag Radhakrishnan , Sarath Nelleri , Navaneeth Poonthottathil

We develop general criteria to construct unified frameworks for inflation and quintessence which employ a unique scalar field to drive both. By using such a minimal theoretical framework we avoid having to fine-tune couplings and…

Astrophysics · Physics 2008-11-26 K. Dimopoulos , J. W. F. Valle