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Related papers: Irreversible Processes in Inflationary Cosmologica…

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Inflationary cosmology has become one of the cornerstones of modern cosmology. Inflation was the first theory within which it was possible to make predictions about the structure of the Universe on large scales, based on causal physics. The…

Astrophysics · Physics 2010-12-09 Robert H. Brandenberger

We consider the non-commutative inflation model of [3] in which it is the unconventional dispersion relation for regular radiation which drives the accelerated expansion of space. In this model, we study the evolution of linear cosmological…

High Energy Physics - Theory · Physics 2008-11-26 Seoktae Koh , Robert H. Brandenberger

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

Cosmological adiabatic particle creation results in the generation of irreversible entropy. The evolution of this entropy is examined in a flat Friedmann--Robertson--Walker universe at late times, using a dissipative model with a power-law…

General Relativity and Quantum Cosmology · Physics 2020-09-16 Nobuyoshi Komatsu

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…

General Relativity and Quantum Cosmology · Physics 2021-01-01 J. R. L. Santos , P. H. R. S. Moraes

This paper consider an universe dominated by baryonic matter, radiation and a nonminimally coupled massive scalar field under the action of a symmetry breaking potential. Inflation occurs naturally with appropriated slow-roll values. The…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-02 S. H. Pereira

Within the framework of the scalar-tensor theory we consider a hill-climbing inflation, in which the effective Planck mass increases in time. We obtain the Einstein frame potential with infinitely long and flat plateau as we approach…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-19 Michal Artymowski , Zygmunt Lalak , Kin-Ya Oda

We derive the quantum energy-momentum tensor and the corresponding quantum equation of state for gauge field theory using the effective Lagrangian approach. The energy-momentum tensor has a term proportional to the space-time metric and…

High Energy Physics - Theory · Physics 2022-01-05 George Savvidy

A model of nonlinear electrodynamics with a dimensional parameter $\beta$ is considered. Electromagnetic fields are the source of the gravitation field and inflation of the universe. We imply that the universe is filled by stochastic…

General Relativity and Quantum Cosmology · Physics 2017-05-08 S. I. Kruglov

The study of particle creation phenomena at the expense of the gravitational field is of great research interest. It might solve the cosmological puzzle single-handedly, without the need for either dark energy or the modified theory of…

General Relativity and Quantum Cosmology · Physics 2018-06-26 Abhik Kumar Sanyal , Subhra Debnath

The inflationary universe can be viewed as a "Cosmological Collider" with energy of Hubble scale, producing very massive particles and recording their characteristic signals in primordial non-Gaussianities. To utilize this collider to…

High Energy Physics - Theory · Physics 2017-07-03 Xingang Chen , Yi Wang , Zhong-Zhi Xianyu

For variable gravity models the strength of gravity, as measured by Newton's ``constant'' or the Planck mass, depends on the value of a scalar field, the cosmon. We discuss two simple four-parameter models with a quadratic or constant…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-15 C. Wetterich

We study an inflation mechanism based on attractor properties in cosmological evolutions of a spatially flat Friedmann-Robertson-Walker spacetime based on the Einstein-scalar field theory. We find a new way to get the Hamilton-Jacobi…

General Relativity and Quantum Cosmology · Physics 2013-12-10 Hyeong-Chan Kim

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

It is accepted in modern cosmology that the scalar field responsible for the inflationary stage of the early Universe is completely transformed into matter. It is assumed that the accelerated expansion is currently driven by dark energy…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-30 G. S. Bisnovatyi-Kogan , A. M. Nikishin

We argue that the emergent spacetime picture admits a background-independent formulation of cosmic inflation. The inflation in this picture corresponds to the dynamical emergence of spacetime while the conventional inflation is simply an…

High Energy Physics - Theory · Physics 2019-02-27 Hyun Seok Yang

Quantum fluctuation of unstable modes about gravitational instantons causes the instability of flat space at finite temperature, leading to the spontaneous process of nucleating quantum black holes. The density of vacuum energy-gain in such…

High Energy Physics - Theory · Physics 2007-05-23 She-Sheng Xue

We present the first quantum field theory model of inflation that is renormalizable in the matter sector, with a super-Hubble inflaton mass and sub-Planckian field excursions, which is thus technically natural and consistent with a…

High Energy Physics - Phenomenology · Physics 2021-01-11 Mar Bastero-Gil , Arjun Berera , Rudnei O. Ramos , João G. Rosa

The reheating process in inflationary universe models is considered as an out-of-equilibrium mixture of two interacting and reacting fluids, and studied within the framework of causal, irreversible thermodynamics. The evolution of the…

Astrophysics · Physics 2016-08-15 Winfried Zimdahl , Diego Pavón , Roy Maartens

Models of cosmic inflation suggest that our universe underwent an early phase of accelerated expansion, driven by the dynamics of one or more scalar fields. Inflationary models make specific, quantitative predictions for several observable…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-10 David I. Kaiser