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Related papers: Cosmic acceleration in entropic cosmology

200 papers

We apply a recent proposal to define "gravitational entropy" to the expansion of cosmic voids within the framework of non-perturbative General Relativity. By considering CDM void configurations compatible with basic observational…

General Relativity and Quantum Cosmology · Physics 2014-08-15 Roberto A. Sussman

Cosmology is undergoing an explosive period of activity, fueled both by new, accurate astrophysical data and by innovative theoretical developments. Cosmological parameters such as the total density of the Universe and the rate of…

Astrophysics · Physics 2007-05-23 A. S. Sakharov , H. Hofer

In this paper, we present an accelerating cosmological model by constraining the free parameters using the cosmological datasets in an extended symmetric teleparallel gravity for the flat and anisotropic space-time. We employ a time…

General Relativity and Quantum Cosmology · Physics 2023-06-27 S. A. Narawade , M. Koussour , B. Mishra

We explore the cosmological implications provided by the geodetic brane gravity action corrected by an extrinsic curvature brane term, describing a codimension-1 brane embedded in a 5D fixed Minkowski spacetime. In the geodetic brane…

General Relativity and Quantum Cosmology · Physics 2012-08-23 Rubén Cordero , Miguel Cruz , Alberto Molgado , Efraín Rojas

We investigate the thermodynamical and causal consistency of cosmological models of the cubic Quasi-Topological Gravity (QTG) in four dimensions, as well as their phenomenological consequences. Specific restrictions on the maximal values of…

General Relativity and Quantum Cosmology · Physics 2013-04-16 U. Camara dS , A. A. Lima , G. M. Sotkov

Cosmological equations were recently derived by Padmanabhan from the expansion of cosmic space due to the difference between the degrees of freedom on the surface and in the bulk in a region of space. In this study, a modified R\'{e}nyi…

General Relativity and Quantum Cosmology · Physics 2017-04-14 Nobuyoshi Komatsu

Class of spherically symmetric Stephani cosmological models is examined in the context of evolution type. It is assumed that the equation of state at the symmetry center of the models is barotropic. Classification of cosmological models is…

Astrophysics · Physics 2009-11-13 Izabela Jakacka , Jerzy Stelmach

We consider the space-time-matter theory (STM) in a five-dimensional vacuum space-time with a generalized FLRW metric to investigate the late-time acceleration of the universe. For this purpose, we derive the four-dimensional induced field…

General Relativity and Quantum Cosmology · Physics 2019-08-20 Raziyeh Zaregonbadi

Most existing cosmological entanglement studies are focused on the isotropic Robertson-Walker (RW) spacetime. Here we go beyond this limitation and study the influence of anisotropy on entanglement generated by dynamical spacetime. Since…

General Relativity and Quantum Cosmology · Physics 2017-11-16 Roberto Pierini , Shahpoor Moradi , Stefano Mancini

This thesis explores the thermodynamics of the cosmological horizon, aiming to make progress towards a better understanding of the microscopic nature of its entropy. We utilise the constrained nature of low-dimensional gravity to do so and…

High Energy Physics - Theory · Physics 2023-10-09 Eleanor Harris

A phenomenological formalism is presented in which the apparent acceleration of the universe is generated by large-scale structure formation, thus eliminating the coincidence and magnitude fine-tuning problems of the Cosmological Constant…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-14 Brett Bochner

Recently it was observed that the hyperbolic compactification of M/string theory related to S-branes may lead to a transient period of acceleration of the universe. We study time evolution of the corresponding effective 4d cosmological…

High Energy Physics - Theory · Physics 2009-09-29 Michael Gutperle , Renata Kallosh , Andrei Linde

We study the dynamics of the homogeneous and isotropic cosmological background in the recently proposed ``quantum phenomenological gravitational dynamics'', characterised by logarithmic corrections to the Bekenstein entropy. We show that…

General Relativity and Quantum Cosmology · Physics 2023-07-21 Marco de Cesare , Giulia Gubitosi

We discuss the testable predictions of a phenomenological model in which the accelerated expansion of the universe is the result of the action of a non-gravitational force field, rather than the effect of a negative-pressure dark-energy…

Astrophysics · Physics 2009-11-13 A. Buzzi , C. Marinoni , S. Colafrancesco

In this research paper, we explore a well-motivated parametrization of the time-dependent deceleration parameter, characterized by a cubic form, within the context of late time cosmic acceleration. The current analysis is based on the…

General Relativity and Quantum Cosmology · Physics 2023-12-19 Madhur Khurana , Himanshu Chaudhary , Saadia Mumtaz , S. K. J. Pacif , G. Mustafa

In view of late-time cosmic acceleration, a dark energy cosmological model is revisited wherein Einstein's cosmological constant is considered as a candidate of dark energy. Exact solution of Einstein field equations (EFEs) is derived in a…

General Relativity and Quantum Cosmology · Physics 2019-11-22 S. K. J. Pacif , Md Salahuddin Khan , L. K. Paikroy , Shalini Singh

We consider an extended scalar-tensor theory of gravity where the action has two interacting scalar fields, a Brans-Dicke field which makes the effective Newtonian constant a function of coordinates and a Higgs field which has derivative…

General Relativity and Quantum Cosmology · Physics 2021-01-13 Soumya Chakrabarti

Stemming from relationships between a number of information describing a system and entropy content of the system it is possible to determine maximal cosmological time. The contribution manifests a compatibility of the superstring theory…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Miroslav Sukenik , Jozef Sima

We discuss the cosmological evolution of a 3-brane Universe in the presence of energy influx from the bulk. We show that this influx can lead to accelerated expansion on the brane, depending on the equations of state of the bulk and brane…

High Energy Physics - Theory · Physics 2009-11-07 N. Tetradis

Cosmic acceleration is widely believed to require either a source of negative pressure (i.e., dark energy), or a modification of gravity, which necessarily implies new degrees of freedom beyond those of Einstein gravity. In this paper we…

High Energy Physics - Theory · Physics 2017-06-28 Lasha Berezhiani , Justin Khoury , Junpu Wang