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Related papers: Inhomogeneous viscous fluids for inflation

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A general overview of the history and present status of inflationary cosmology is given. Recent developments discussed in this paper include the hybrid inflation scenario, the theory of reheating, and the theory of inflating tolopogical…

High Energy Physics - Theory · Physics 2007-05-23 Andrei Linde

The main aim of this paper is to provide a qualitative introduction to the cosmic inflation and its relationship with current cosmological observations. The inflationary model solves many of the fundamental problems that challenge the…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-24 J. Alberto Vazquez , Luis E. Padilla , Tonatiuh Matos

We examine the cosmological consequences of an alternative to the standard expression for bulk viscosity, one which was proposed to avoid the propagation of superluminal signals without the necessity of extending the space of variables of…

General Relativity and Quantum Cosmology · Physics 2016-04-08 Marcelo M. Disconzi , Thomas W. Kephart , Robert J. Scherrer

Many pedagogical introductions of cosmological inflation are effective due to the simplicity of the relevant equations. Here an analytic solution of the cosmological equations is presented and used as an example to discuss fundamental…

Physics Education · Physics 2009-11-06 Valerio Faraoni

Modifying the standard hot big bang model of cosmology with an inflationary event has been very successful in resolving most of the outstanding cosmological problems. The various inflationary mechanisms proposed depend on the production of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Akinbo Ojo

The holographic principle in a radiation dominated universe, as discussed first by Verlinde (2000), is extended so as to incorporate the case of a bulk-viscous cosmic fluid. This corresponds to a non-conformally invariant theory.…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Iver Brevik

Recently, few cosmological models with additional non-Riemannian volume form(s) have been proposed. In this article we use Supernovae type Ia experimental data to test one of these models which provides a unified description of both dark…

General Relativity and Quantum Cosmology · Physics 2018-10-05 Denitsa Staicova , Michail Stoilov

In this paper, we have investigated the possibility to have inflation from inhomogeneous viscous fluids by taking into account the brane correction coming from string-inspired five dimensional Einsten's gravity. We have realized several…

General Relativity and Quantum Cosmology · Physics 2015-09-21 Ratbay Myrzakulov , Lorenzo Sebastiani

Holography is expected as one of the promising descriptions of quantum general relativity. We present a model for a cosmological system involving two holographic screens and find that their equilibrium exactly yields a standard…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Yi-Fu Cai , Jie Liu , Hong Li

We propose a method to extract predictions from quantum cosmology for inflation that can be confronted with observations. Employing the tunneling boundary condition in quantum geometrodynamics, we derive a probability distribution for the…

General Relativity and Quantum Cosmology · Physics 2015-07-21 Gianluca Calcagni , Claus Kiefer , Christian F. Steinwachs

The very basics of cosmological inflation are discussed. We derive the equations of motion for the inflaton field, introduce the slow-roll parameters, and present the computation of the inflationary perturbations and their connection to the…

General Relativity and Quantum Cosmology · Physics 2012-01-31 K. Enqvist

We propose a cosmological model that describes isotropic expansion of inhomogeneous universe. The energy-momentum tensor that creates the spatial inhomogeneity may not affect the uniform expansion scaling factor $a(t)$ in the FLRW-like…

High Energy Physics - Theory · Physics 2014-10-15 Wei-Jian Geng , H. Lu

Inflationary homogeneous isotropic cosmological models filled by scalar fields and ultrarelativistic matter are examined in the framework of gauge theories of gravitation. By using quadratic scalar field potential numerical analysis of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 A. V. Minkevich , A. S. Garkun

Scalar and tensorial cosmological perturbations generated in warm inflationary scenarios whose matter-radiation fluid is endowed with a viscous pressure are considered. Recent observational data from the WMAP experiment are employed to…

Astrophysics · Physics 2008-11-26 Sergio del Campo , Ramon Herrera , Diego Pavon

In the hope of avoiding model dependence of the cosmological observables, phenomenological parametrizations of Cosmic Inflation have recently been proposed. Typically, they are expressed in terms of two parameters associated with an…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-16 Jerome Martin , Christophe Ringeval , Vincent Vennin

We review the role of fluids in cosmology by first introducing them in General Relativity and then by applying them to a FRW Universe's model. We describe how relativistic and non-relativistic components evolve in the background dynamics.…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-24 Jorge L. Cervantes-Cota , Jaime Klapp

The big bang model and the history of the early universe according to the grand unified theories are introduced. The shortcomings of big bang are discussed together with their resolution by inflationary cosmology. Inflation, the subsequent…

High Energy Physics - Phenomenology · Physics 2008-11-26 G. Lazarides

We investigate the emergent universe scenario in the presence of interacting fluids. The non-linear equation of state (EoS) considered in the general theory of relativity for obtaining emergent universe is effectively a cosmological model…

General Relativity and Quantum Cosmology · Physics 2015-05-20 B. C. Paul , A. S. Majumdar

A generalization of the random fluid hydrodynamic fluctuation theory due to Landau and Lifshitz is applied to describe cosmological fluctuations in systems with radiation and scalar fields. The viscous pressures, parametrized in terms of…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-14 Mar Bastero-Gil , Arjun Berera , Ian G. Moss , Rudnei O. Ramos

We consider the cosmological application of a (variant of) relatively newly proposed model \cite{1609.06915} unifying inflation, dark energy, dark matter, and the Higgs mechanism. The model was originally defined using additional…

General Relativity and Quantum Cosmology · Physics 2019-06-21 Denitsa Staicova , Michail Stoilov