English
Related papers

Related papers: Inflation driven by q-de Sitter

200 papers

Within the framework of geometric inflation, where the Friedmann equation is modified to incorporate an infinite series of higher curvature corrections, we describe the emergence of a de Sitter inflationary phase near the poles of an…

High Energy Physics - Theory · Physics 2025-06-23 Adolfo Cisterna , Nicolas Grandi , Julio Oliva

We investigate chaotic inflation models with two scalar fields, such that one field (the inflaton) rolls while the other is trapped in a false vacuum state. The false vacuum becomes unstable when the inflaton field falls below some critical…

Astrophysics · Physics 2009-10-22 Edmund J Copeland , Andrew R Liddle , David H Lyth , Ewan D Stewart , David Wands

A unified multi scalar field model with three flat regions is discussed. The three flat regions are the inflation, early and late dark energy epochs. The potential is obtained by a spontaneous breaking of scale invariance generated by Non…

General Relativity and Quantum Cosmology · Physics 2022-06-22 Eduardo Guendelman , Ramon Herrera , David Benisty

Picking out DBI scalar field as inflation, the slow-rolling inflationary scenario is studied by attributing an exponential time function to scale factor; known as intermediate inflation. The perturbation parameters of the model are…

General Relativity and Quantum Cosmology · Physics 2017-08-15 N. Nazavari , A. Mohammadi , Z. Ossoulian , Kh. Saaidi

In the framework of geometrothermodynamics, we explore how to construct an inflationary cosmic fluid without requiring inflaton fields. To do so, we employ standard radiation and matter as barotropic background, speculating on the existence…

General Relativity and Quantum Cosmology · Physics 2024-07-03 Jesus Anaya-Galeana , Orlando Luongo , Hernando Quevedo

We study a scale-invariant model of quadratic gravity with a non-minimally coupled scalar field. We focus on cosmological solutions and find that scale invariance is spontaneously broken and a mass scale naturally emerges. Before the…

General Relativity and Quantum Cosmology · Physics 2016-07-13 Massimiliano Rinaldi , Luciano Vanzo

In a unified picture both inflation and present dynamical dark energy arise from the same scalar field. The history of the Universe describes a crossover from a scale invariant "past fixed point" where all particles are massless, to a…

High Energy Physics - Theory · Physics 2015-12-09 C. Wetterich

We study a model cosmological solution of the coupled Einstein, electromagnetic (with source) and second-gravity \cite{Nash2010} equations that employs a flat universe Friedmann-\text{Lema{\^ \i}tre}-Robertson-Walker (FLRW) line element…

Cosmology and Nongalactic Astrophysics · Physics 2015-04-16 Patrick Lee Nash

We show that in the Feebly Interacting Massive Particle (FIMP) model of Dark Matter (DM), one may express the inflationary energy scale $H_*$ as a function of three otherwise unrelated quantities, the DM isocurvature perturbation amplitude,…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-21 Kari Enqvist , Robert J. Hardwick , Tommi Tenkanen , Vincent Vennin , David Wands

Phantom Cosmology provides an unique opportunity to "connect" the phantom driven (low en- ergy meV scale) dark energy phase to the (high energy GUT scale) inflationary era. This is possible because the energy density increases in phantom…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-29 Cosmin Ilie , Tirthabir Biswas , Katherine Freese

Recently, attempts have been made to understand the apparent near coincidence of the present dark energy and matter energy in terms of a dynamical attractor-like solution for the evolution of a scalar field. In these models the field…

Astrophysics · Physics 2009-11-06 M. Yahiro , G. J. Mathews , K. Ichiki , T. Kajino , M. Orito

Motivated by the idea that inflation occurs at the GUT symmetry breaking scale, in this paper we construct a new class of large field inflaton potentials where the inflaton starts with a power law potential; after initial period of relative…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-24 Dhiraj Kumar Hazra , Arman Shafieloo , George F. Smoot , Alexei A. Starobinsky

Scalar-tensor theory of gravity with non-minimal coupling is a fairly good candidate for dark energy, required to explain late-time cosmic evolution. Here we study the very early stage of evolution of the universe with a modified version of…

High Energy Physics - Theory · Physics 2018-05-22 Ranajit Mandal , Chandramouli Sarkar , Abhik Kumar Sanyal

Inflation creates perturbations for the large scale structures in the universe, but it also dilutes everything. Therefore it is pertinent that the end of inflation must explain how to excite the Standard Model {\it dof} along with the dark…

High Energy Physics - Phenomenology · Physics 2013-07-22 Lingfei Wang , Ernestas Pukartas , Anupam Mazumdar

Recently an inflationary model with a vector field coupled to the inflaton was proposed and the phenomenology studied for the Bianchi type I spacetime. It was found that the model demonstrates a counter-example to the cosmic no-hair theorem…

General Relativity and Quantum Cosmology · Physics 2011-12-22 Sigbjørn Hervik , David F. Mota , Mikjel Thorsrud

We show that there are inflationary models for which perturbations in the energy momentum tensor, which are of second order in the scalar field, cannot be neglected. We first specify the conditions under which the usual first order…

Astrophysics · Physics 2009-10-22 R. Durrer , M. Sakellariadou

The current epoch of accelerated cosmic expansion is postulated to be driven by dark energy, which in the standard model takes the form of a cosmological constant with equation of state parameter $w=-1$. We propose an innovative perspective…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-17 Sveva Castello , Stéphane Ilić , Martin Kunz

We study chaotic inflation driven by a real, massive, homogeneous minimally coupled scalar field in a flat Robertson-Walker spacetime. The semiclassical limit for gravity is considered, whereas the scalar field is treated quantum…

General Relativity and Quantum Cosmology · Physics 2008-11-26 F. Finelli , G. P. Vacca , G. Venturi

We investigate the warm inflationary scenario within the context of the linear version of f (Q, T ) gravity, coupled with both the inflaton scalar field and the radiation field, under the conditions of the strong dissipation regime. First,…

General Relativity and Quantum Cosmology · Physics 2024-08-14 Maryam Shiravand , Mehrdad Farhoudi , Parviz Goodarzi

In inflationary cosmology the quasi de Sitter graceful exit allows us to measure the quantum features of the primordial dS phase, in particular, the lack of scale invariance parametrized by the spectral index $n_s$. In this review we…

High Energy Physics - Theory · Physics 2022-05-05 Cesar Gomez , Raul Jimenez
‹ Prev 1 8 9 10 Next ›