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Related papers: Analytic Singular Slow-roll Inflation

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Here we concisely review the nonminimal coupling dynamics of a single scalar field in the context of purely affine gravity and extend the study to multifield dynamics. The coupling is performed via an affine connection and its associated…

General Relativity and Quantum Cosmology · Physics 2018-06-01 Hemza Azri

The analyticity of response functions and scattering amplitudes implies powerful relations between low-energy observables and the underlying short-distance dynamics. These 'IR/UV' relations are rooted in basic physical principles, such as…

High Energy Physics - Theory · Physics 2016-02-03 Daniel Baumann , Daniel Green , Hayden Lee , Rafael A. Porto

In this work we shall study $k$-inflation theories with non-minimal coupling of the scalar field to gravity, in the presence of only a higher order kinetic term of the form $\sim \mathrm{const}\times X^{\mu}$, with…

General Relativity and Quantum Cosmology · Physics 2021-01-05 V. K. Oikonomou

We investigate all single-field, slow-roll inflationary models whose slow-roll parameters scale as 1/N in the limit of a large number of e-folds N. We proof that all such models belong to two universality classes, characterised by a single…

High Energy Physics - Theory · Physics 2015-06-17 Diederik Roest

The linear and quadratic perturbations for a scalar-tensor model with non-minimal coupling to curvature, coupling to the Gauss-Bonnet invariant and non-minimal kinetic coupling to the Einstein tensor are developed. The quadratic action for…

General Relativity and Quantum Cosmology · Physics 2019-09-24 L. N. Granda , D. F. Jimenez

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

The single scalar field inflationary models that lead to scalar and tensor perturbation spectra with amplitudes varying in direct proportion to one another are reconstructed by solving the Stewart-Lyth inverse problem to next-to-leading…

Astrophysics · Physics 2009-11-07 C. A. Terrero-Escalante , James E. Lidsey , Alberto A. Garcia

We briefly review the arising of an inflationary phase in the Universe evolution in order to discuss an inhomogeneous cosmological solution in presence of a real self interacting scalar field minimally coupled to gravity in the region of a…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Giovanni Imponente

We examine cosmological inflation in a broad family of scalar-tensor models characterized by scalar-dependent non minimal kinetic couplings and Gauss-Bonnet terms. Using a slow roll-approximation, we compute in detail theoretical…

High Energy Physics - Theory · Physics 2026-05-21 A. Belhaj , H. Es-Sobbahi , M. Oualaid , E. Torrente-Lujan

Generalized slow roll conditions and parameters are obtained for a general form of scalar-tensor theory (with no external sources), having arbitrary functions describing a nonminimal gravitational coupling F(\phi), a Kahler-like kinetic…

General Relativity and Quantum Cosmology · Physics 2009-11-07 J. R. Morris

Usual inflation is realized with a slow rolling scalar field minimally coupled to gravity. In contrast, we consider dynamics of a scalar with a flat effective potential, conformally coupled to gravity. Surprisingly, it contains an attractor…

High Energy Physics - Theory · Physics 2008-11-26 Lev Kofman , Shinji Mukohyama

The conventional slow-roll approximation is broken in the so-called "ultra slow-roll" models of inflation, for which the inflaton potential is exactly (or extremely) flat. The interesting nature of (canonical) ultra slow-roll inflation is…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-18 Shin'ichi Hirano , Tsutomu Kobayashi , Shuichiro Yokoyama

Most models of inflation have small parameters, either to guarantee sufficient inflation or the correct magnitude of the density perturbations. In this paper we show that, in supersymmetric theories with weak scale supersymmetry breaking,…

High Energy Physics - Phenomenology · Physics 2007-05-23 Lisa Randall , Marin Soljacic , Alan Guth

In this work, we investigate how a smooth transition from a constant-roll to a slow-roll inflationary era may be realized, in the context of a canonical scalar field theory. We study in some detail the dynamical evolution of the…

General Relativity and Quantum Cosmology · Physics 2018-02-14 V. K. Oikonomou

The conventional background solution for the evolution of a single canonical inflaton field performs admirably in extreme scenarios such as the slow-roll phase (where the slow-roll parameter is much less than one) and the deep reheating era…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-26 Manjeet Kaur , Debottam Nandi , Sharath Raghavan B

This paper revisits the Inflationary scenario within the framework of scalar field models possessing a non-canonical kinetic term. We obtain closed form solutions for all essential quantities associated with chaotic inflation including slow…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-03 Sanil Unnikrishnan , Varun Sahni , Aleksey Toporensky

We investigate the entanglement due to geometric corrections in particle creation during inflation. To do so, we propose a single-field inflationary scenario, nonminimally coupled to the scalar curvature of spacetime. We require particle…

General Relativity and Quantum Cosmology · Physics 2023-06-05 Alessio Belfiglio , Orlando Luongo , Stefano Mancini

In this work we generalize the constant-roll condition for minimally coupled canonical scalar field inflation. Particularly, we shall assume that the scalar field satisfies the condition $\ddot{\phi}=\alpha (\phi) V'(\phi)$, and we derive…

General Relativity and Quantum Cosmology · Physics 2022-05-25 V. K. Oikonomou

We often find in the literature solutions to the Friedmann and fluid equations for simple cosmological models during the matter, radiation or cosmological constant dominated epochs. However no solutions appear for the inflationary era…

General Relativity and Quantum Cosmology · Physics 2020-07-30 Gabriel German

We provide a refined and much more simplified Einstein-Gauss-Bonnet inflationary theoretical framework, which is compatible with the GW170817 observational constraints on the gravitational wave speed. As in previous works, the constraint…

General Relativity and Quantum Cosmology · Physics 2021-09-22 V. K. Oikonomou