Related papers: Hyperbolic inflation in the Jordan frame
We study inflation induced by (power-low) scalar curvature corrections to General Relativity. The class of inflationary scalar potentials $V(\sigma)\sim\exp[n\,\sigma]$, $n$ general parameter, is investigated in the Einsein frame and the…
We here explore a specific class of scalar field, dubbed quasi-quintessence which exhibits characteristics akin to ordinary matter. Specifically, we investigate under which conditions this fluid can mitigate the classical cosmological…
Inflation models based on scalar-tensor theories of gravity are formulated in the Jordan frame but most often analysed in the Einstein frame. The transformation between the frames is not always desirable. In this work we formulate slow-roll…
We investigate inflation models in Jordan frame supergravity, in which an inflaton non-minimally couples to the scalar curvature. By imposing the condition that an inflaton would have the canonical kinetic term in the Jordan frame, we…
We investigate a Jordan-Brans-Dicke (JBD) scalar field, $\Phi$, with power-law potential in the presence of a second scalar field, $\phi$, with an exponential potential, in both the Jordan and the Einstein frames. We present the relation of…
Cosmological alpha-attractors give a natural explanation for the spectral index n_s of inflation as measured by Planck while predicting a range for the tensor-to-scalar ratio r, consistent with all observations, to be measured more…
One common approach for cosmic inflation consists in couple Einstein's gravity with a scalar field, often referred to inflaton field. In order to derive analytic simple scenarios, we usually work in the {\it slow-roll} regime. In such an…
Physical equivalence between different conformal frames in scalar-tensor theory of gravity is a known fact. However, assuming that matter minimally couples to the metric of a particular frame, which we call the matter Jordan frame, the…
In this paper, we extend a recent proposed model of two scalar and two vector fields to a hyperbolic inflation scenario, in which the field space of two scalar fields is a hyperbolic space instead of a flat space. In this model, one of the…
We investigate the global dynamics of the field equations of (pure) quadratic theories of gravity which generalise Einstein's theory in spatially flat homogeneous and isotropic cosmological models with a perfect fluid. We introduce global…
The FRW model with non-minimally coupled massive scalar field has been investigated in LQC framework. Considered form of the potential and coupling allows applications to Higgs driven inflation. Out of two frames used in the literature to…
We demonstrate the attractor behavior of inflation driven by a scalar field or a tachyon field in the context of recently proposed four-dimensional effective gravity induced on the world-volume of a three-brane in five-dimensional Einstein…
We explore inflationary cosmology in a theory where there are two scalar fields which non-minimally couple to the Ricci scalar and an additional $R^2$ term, which breaks the conformal invariance. Particularly, we investigate the slow-roll…
An introductory, self-contained overview, with pedagogical figures, is provided to acquaint readers unfamiliar with the subjects with key aspects of de Sitter space and inflation. The connection between de Sitter space and cosmology is…
Inflation based on scalar fields which are non-minimally coupled to gravity has been proposed as a way to unify inflation with weak-scale physics, with the inflaton being identified with the Higgs boson or other weak-scale scalar article.…
The induced gravity theory is a variant of Jordan--Brans--Dicke theory where the `dilaton' field possesses a potential. It has the unusual feature that in the presence of a false vacuum there is a {\em stable} static solution with the…
Cosmological solutions of the Brans-Dicke theory with an added cosmological constant are investigated with an emphasis to select a conformal frame in order to implement the scenario of a decaying cosmological constant, featuring an ever…
We consider two kinds of higher dimensional models which upon dimensional reduction lead to Jordan-Brans-Dicke type effective actions in four dimensions with the scale factor of the extra dimensions playing the role of the JBD field. These…
A model of cosmological inflation is proposed in which field space is a hyperbolic plane. The inflaton never slow-rolls, and instead orbits the bottom of the potential, buoyed by a centrifugal force. Though initial velocities redshift away…
We review the attractor properties of the simplest chaotic model of inflation, in which a minimally coupled scalar field is endowed with a quadratic scalar potential. The equations of motion in a flat Friedmann-Robertson-Walker universe are…