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Related papers: Modified cosmology through Barrow entropy

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In this work, we analyse the late-time evolution of the universe for a particular $f(R)$ gravity model built from an exponential function of the scalar curvature. Following the literature, we write the field equations in terms of a suited…

General Relativity and Quantum Cosmology · Physics 2023-10-18 A. Oliveros , Mario A. Acero

We have extended our result on defocussing of world lines [1] by modifying gravity in the early epoch by a 5-d theory with scalar $\psi(r)$. The acceleration term in the Raychaudhuri equation has been shown to be positive for flat FRW…

General Physics · Physics 2020-04-22 R Parthasarathy

Following a paper by Berman and Marinho Jr (2001), where it was established an equation of state (p=-(1/3)rho), for the very early Universe, under which, Einstein's equations with lambda=0, render a scale-factor proportional to the time…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Marcelo Samuel Berman

A cubic correction of $f(T)$ gravity, where $T$ is the teleparallel scalar torsion, is considered to describe gravity in spatially flat Friedmann-Robertson-Walker model. A scale factor permitting departure from inflation era has been…

General Physics · Physics 2015-11-06 G. G. L. Nashed , W. El Hanafy

The simplest cosmology --- the Friedmann-Robertson-Walker-Lema\^{i}tre (FRW) model --- describes a spatially homogeneous and isotropic universe where the scale factor is the only dynamical parameter. Here we consider how quantized…

Quantum Physics · Physics 2017-10-11 J. A. Smiga , J. M. Taylor

We study cosmologies in modified theories of gravity considering Lagrangian density $f(R)$ which is a polynomial function of scalar curvature ($R$) in the Einstein-Hilbert action in vacuum. The field equation obtained from the modified…

Cosmology and Nongalactic Astrophysics · Physics 2009-10-29 B. C. Paul , P. S. Debnath , S. Ghose

We study some aspects of cosmologies in 5D models with one infinite extra dimension. Matter is confined to the brane, gravity extends to the bulk. Models with positive and negative tension of the brane are considered. Cosmological evolution…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Mikhail Z. Iofa

This paper investigates the cosmological implications of the modified gravity framework known as $f(R,\Sigma, T)$ gravity, focusing on its potential to unify and extend current cosmological models. The theory, introduced by Bakry and…

General Relativity and Quantum Cosmology · Physics 2025-03-04 N. Myrzakulov , S. H. Shekh , Anirudh Pradhan

In this paper, using Barrow entropy, we propose an interacting model of Barrow holographic dark energy (BHDE). In particular, we study the evolution of a spatially flat FLRW universe composed of pressureless dark matter and BHDE that…

General Relativity and Quantum Cosmology · Physics 2021-01-26 Abdulla Al Mamon , Andronikos Paliathanasis , Subhajit Saha

In this paper we investigate dynamics of the modified loop quantum cosmology models using dynamical systems methods. Modifications considered come from the choice of the different field strength operator $\hat{F}$ and result in different…

General Relativity and Quantum Cosmology · Physics 2014-11-18 Orest Hrycyna , Jakub Mielczarek , Marek Szydlowski

Recent measurements of type Ia supernovae as well as other concordant observations suggest that the expansion of our universe is accelerating. A dark energy component has usually been invoked as the most feasible mechanism for the…

Astrophysics · Physics 2014-10-13 Zong-Hong Zhu , Masa-Katsu Fujimoto , Xiang-Tao He

In this paper, we study $F(R)$ gravity by Hu-Sawicki model in Friedmann-Lema\^{\i}tre-Robertson-Walker (FLRW) background. The Friedmann equations are calculated by modified gravity action, and then the obtained Friedmann equations are…

General Relativity and Quantum Cosmology · Physics 2016-05-25 Ali R. Amani

Modified cosmology based on Barrow entropy arises from the gravity-thermodynamics conjecture, in which the standard Bekenstein-Hawking entropy is replaced by the Barrow entropy of quantum-gravitational origin, characterized by the Barrow…

General Relativity and Quantum Cosmology · Physics 2025-09-08 Giuseppe Gaetano Luciano , Andronikos Paliathanasis , Emmanuel N. Saridakis

The current standard cosmological model is constructed within the framework of general relativity with a cosmological constant $\Lambda$, which is often associated with dark energy, and phenomenologically explains the accelerated cosmic…

General Relativity and Quantum Cosmology · Physics 2023-06-27 Jiamin Hou , Julian Bautista , Maria Berti , Carolina Cuesta-Lazaro , César Hernández-Aguayo , Tilman Tröster , Jinglan Zheng

In a recent paper (Vigoureux et al. Int. J. Theor. Phys. 47:928, 2007) it has been suggested that the velocity of light and the expansion of the universe are two aspects of one single concept connecting space and time in the expanding…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-22 David Viennot , Jean-Marie Vigoureux

First a Friedmann-Robertson-Walker (FRW) universe filled with dust and a conformally invariant scalar field is quantized. For the closed model we find a discrete set of wormhole quantum states. In the case of flat spacelike sections we find…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Nivaldo A. Lemos , Flavio G. Alvarenga

We study the classical and quantum models of a Friedmann-Robertson-Walker (FRW) cosmology, coupled to a perfect fluid, in the context of the scalar-metric gravity. Using the Schutz' representation for the perfect fluid, we show that, under…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Babak Vakili

Recently, it was formulated a teleparallel theory called $f(T,B)$ gravity which connects both $f(T)$ and $f(R)$ under suitable limits. In this theory, the function in the action is assumed to depend on the torsion scalar $T$ and also on a…

General Relativity and Quantum Cosmology · Physics 2017-12-19 Sebastian Bahamonde , M. Zubair , G. Abbas

The present standard model of cosmology, $\Lambda$CDM, contains some intriguing coincidences. Not only are the dominant contributions to the energy density approximately of the same order at the present epoch, but we note that contrary to…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Pim van Oirschot , Juliana Kwan , Geraint F. Lewis

We study the effects of an information-theoretically motivated nonlinear correction to the Wheeler-deWitt equation in the minisuperspace scheme for flat, $k=0$, Friedmann-Robertson-Walker (FRW) universes. When the only matter is a…

General Relativity and Quantum Cosmology · Physics 2014-11-18 Le-Huy Nguyen , Rajesh R. Parwani
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