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Related papers: Quintessential constant-roll inflation

200 papers

We explore the inflationary phase of a scalar field with a kinetic term non-minimally coupled to gravity. We find that one of the slow-roll conditions is naturally consequence of the equation of motion of the scalar field. Thus, slow-roll…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-16 Amir Ghalee

We obtain cosmological constraints on models of inflation which exhibit rapid roll solutions. Rapid roll attractors exist for potentials with large mass terms and are thus of interest for inflationary model building within string theory. We…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-15 Takeshi Kobayashi , Shinji Mukohyama , Brian A. Powell

We adopt the double field natural inflation model motivated by the non-perturbative effects of supergravity and superstring theory to do the slow roll analysis. We show that when the parameters are suitably chosen, there exist ranges of…

General Relativity and Quantum Cosmology · Physics 2019-04-12 Ping Kwan Man Ellgan

We provide an update on five relatively well motivated inflationary models in which the inflaton is a Standard Model singlet scalar field. These include i) the textbook quadratic and quartic potential models but with additional couplings of…

High Energy Physics - Phenomenology · Physics 2016-04-28 Nobuchika Okada , Vedat Nefer Şenoğuz , Qaisar Shafi

In this note we point out that, contrary to the standard point of view, slow roll inflation is due to high gravitational friction. We show that the requirement of slow roll coincides with the requirement of a flat scalar field potential in…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-07 Cristiano Germani

We investigate the constant-roll inflation with non-minimally kinetic coupling to the Einstein tensor. With the slow-roll parameter $\eta_\phi = -\ddot{\phi}/(H\dot{\phi})$ being a constant, we calculate the power spectra for scalar and…

General Relativity and Quantum Cosmology · Physics 2024-07-22 Jie Liu , Yungui Gong , Zhu Yi

I consider the question of possible observability of the total number of e-folds accumulated during the epoch of inflation. The total number of observable e-folds has been previously constrained by the de Sitter entropy after inflation,…

General Relativity and Quantum Cosmology · Physics 2010-03-09 Sergei Winitzki

We investigate the measure problem in the framework of inflationary cosmology. The measure of the history space is constructed and applied to inflation models. Using this measure, it is shown that the probability for the generalized single…

High Energy Physics - Theory · Physics 2010-10-27 Miao Li , Yi Wang

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 investigate the observational viability of a class of $\alpha$-attractors inflationary models in light of the most recent Cosmic Microwave Background (CMB) and Large-Scale Structure (LSS) data. By considering a double-well potential we…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-04 J. G. Rodrigues , S. Santos da Costa , J. S. Alcaniz

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

If the inflaton and the quintessence fields are identified, the background geometry evolves through a stiff epoch undershooting the expansion rate of a radiation-dominated plasma. For some classes of inflationary potentials this scenario is…

General Relativity and Quantum Cosmology · Physics 2020-01-08 Massimo Giovannini

We investigate the cosmic inflation within a class of the scalar-tensor model with the scalar-dependent non-minimal kinetic couplings. The inflationary dynamical potential will be applied. Using the slow-roll approximation, we compute…

General Relativity and Quantum Cosmology · Physics 2025-12-01 Feyzollah Younesizadeh , Davoud Kamani

We consider inflation in a universe with a positive cosmological constant and a nonminimally coupled scalar field, in which the field couples both quadratically and quartically to the Ricci scalar. When considered in the Einstein frame and…

General Relativity and Quantum Cosmology · Physics 2015-08-21 Dražen Glavan , Anja Marunović , Tomislav Prokopec

We consider the behaviour of a quintessence field during an inflationary epoch, in order to learn how inflation influences the likely initial conditions for quintessence. We use the stochastic inflation formalism to study quantum…

Astrophysics · Physics 2009-11-07 Michael Malquarti , Andrew R Liddle

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

Within the effective field theory of inflation, an initialization of the classical dynamics of the inflaton with approximate equipartition between the kinetic and potential energy of the inflaton leads to a brief fast roll stage that…

Astrophysics · Physics 2009-11-11 D. Boyanovsky , H. J. de Vega , N. G. Sanchez

We consider inflationary models with the inflaton coupled to the Gauss-Bonnet term assuming a special relation $\delta_1=2\lambda\epsilon_1$ between the two slow-roll parameters $\delta_1$ and $\epsilon_1$. For the slow-roll inflation, the…

General Relativity and Quantum Cosmology · Physics 2018-10-19 Zhu Yi , Yungui Gong , Mudassar Sabir

We consider the polynomial inflation with the tensor-to-scalar ratio as large as possible which can be consistent with the Quantum Gravity (QG) corrections and Effective Field Theory (EFT). To get a minimal field excursion $\Delta\phi$ for…

General Relativity and Quantum Cosmology · Physics 2021-07-07 Lina Wu , Qing Gao , Yungui Gong , Yiding Jia , Tianjun Li

We propose new slow-roll approximations for inflationary models with the Gauss-Bonnet term. We find more accurate expressions of the standard slow-roll parameters as functions of the scalar field. To check the accuracy of approximations…

General Relativity and Quantum Cosmology · Physics 2024-09-24 Ekaterina O. Pozdeeva , Maria A. Skugoreva , Alexey V. Toporensky , Sergey Yu. Vernov