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Related papers: Generic analysis of kinetically driven inflation

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We consider the well motivated model of the (standard) supersymmetric F-term hybrid inflation (FHI) which can be realized close to the grand unification scale. The predicted scalar spectral index $n_s$ cannot be smaller than 0.98 and can…

High Energy Physics - Phenomenology · Physics 2015-05-13 C. Pallis

We study the dynamics of multiple scalar fields and a barotropic fluid in an FLRW-universe. The scalar potential is a sum of exponentials. All critical points are constructed and these include scaling and de Sitter solutions. A stability…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Jelle Hartong , André Ploegh , Thomas Van Riet , Dennis B. Westra

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

Inflation models can have an early phase of inflation where the evolution of the inflaton is driven by quantum fluctuations before entering the phase driven by the slope of the scalar field potential. For a Coleman-Weinberg potential this…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-06 Arjun Berera , Raghavan Rangarajan

There are many inflationary models in which inflaton field does not satisfy the slow-roll condition. However, in such models, it is always difficult to generate the curvature perturbation during inflation. Thus, to generate the curvature…

High Energy Physics - Phenomenology · Physics 2009-11-11 Tomohiro Matsuda

We study the dynamics of inflation in a generalized scalar-torsion gravity scenario by assuming a canonical scalar field non-minimally coupled to torsion with a Galileon-type self-interaction. After obtaining the field equations for a flat…

General Relativity and Quantum Cosmology · Physics 2019-08-26 Manuel Gonzalez-Espinoza , Giovanni Otalora , Nelson Videla , Joel Saavedra

We study generalized Galileons as a framework to develop the most general single-field inflation models ever, Generalized G-inflation, containing yet further generalization of G-inflation, as well as previous examples such as k-inflation,…

High Energy Physics - Theory · Physics 2011-11-03 Tsutomu Kobayashi , Masahide Yamaguchi , Jun'ichi Yokoyama

Quantization implies independent degrees of freedom that do not appear in the classical theory, given by fluctuations, correlations, and higher moments of a state. A systematic derivation of the resulting dynamical systems is presented here…

High Energy Physics - Theory · Physics 2021-08-24 Martin Bojowald , Suddhasattwa Brahma , Sean Crowe , Ding Ding , Joseph McCracken

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

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

A general form of warm inflation with the dissipative coefficient $\Gamma=\Gamma_0(\phi /\phi_0) ^n(T/\tau_0) ^m$ in loop quantum cosmology is studied. In this case, we obtain conditions for the existence of a warm inflationary attractor in…

General Relativity and Quantum Cosmology · Physics 2015-06-12 Xiao-Min Zhang , Jian-Yang Zhu

As part of our program to develop a general theory of relativity for open systems, we introduce a covariant theory that incorporates the effects of classical and quantum spacetime alterations in a new metric tensor that effectively includes…

General Relativity and Quantum Cosmology · Physics 2025-09-25 Alan Sebastián Morales , Mauricio Bellini , Juan Ignacio Musmarra

If the expansion of the early Universe was not close to de Sitter, the statistical imprints of the primordial density perturbation on the cosmic microwave background can be quite different from those derived in slow-roll inflation. In this…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-05 Raquel H. Ribeiro

In this paper, inflationary cosmology is reviewed, paying particular attention to its observational signatures associated with large-scale density perturbations generated from quantum fluctuations. In the most general scalar-tensor theories…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-13 Shinji Tsujikawa

The observed classicality of primordial perturbations, despite their quantum origin during inflation, calls for a mechanism for quantum-to-classical transition of these initial fluctuations. As literature suggests a number of plausible…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-01 Shreya Banerjee , Suratna Das , K. Sravan Kumar , T. P. Singh

Inflationary models are usually based on dynamics of one or more scalar fields coupled to gravity. In this work we present a new class of inflationary models, gauge-flation or non-Abelian gauge field inflation, where slow-roll inflation is…

High Energy Physics - Phenomenology · Physics 2015-03-18 A. Maleknejad , M. M. Sheikh-Jabbari

We investigate the models of cosmological inflation in generalized scalar-tensor gravity, which we consider as a source of deviation from de Sitter dynamics in the case of GR. Within the framework of the proposed approach, the exact…

General Relativity and Quantum Cosmology · Physics 2018-12-05 Igor V. Fomin , Sergey V. Chervon

In this paper, we explore the inflationary dynamics of the $\beta$-exponential potential model, where a scalar field couples to quadratic $(R + R^2)$ gravity. In this model, the inflaton is the field that determines the size of the extra…

General Relativity and Quantum Cosmology · Physics 2026-01-15 Ozan Sargın

Inverted hybrid inflation (in which the inflaton field slowly rolls away from the origin, giving a spectral index $n\lsim 1$) is an appealing variant of the more usually studied hybrid model. Analysing the model alongside the ordinary…

High Energy Physics - Phenomenology · Physics 2009-10-30 S. F. King , J. Sanderson

We study the possibility that inflation is driven by a scalar field together with a vector field minimally coupled to gravity. By assuming an effective potential that incorporates both fields into the action, we explore two distinct…

General Relativity and Quantum Cosmology · Physics 2024-12-09 Manuel Gonzalez-Espinoza , Ramon Herrera