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Related papers: An entropy-driven cosmic expansion

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In the context of f(R, T) gravity theory for the flat Friedmann Lemaitre Robertson Walker (FLRW) model, the accelerating expansion of the universe is investigated using a specific form of the emergent Hubble parameter. Datasets from H(z),…

General Relativity and Quantum Cosmology · Physics 2025-01-16 N. Myrzakulov , S. H. Shekh , Anirudh Pradhan , Archana Dixit

We study the time evolution of entanglement entropy in expanding universes with various matters. To describe expanding universes holographically, we take into account a braneworld moving in an asymptotic AdS space involving a uniform…

High Energy Physics - Theory · Physics 2023-01-18 Chanyong Park

It is shown that density fluctuations obey a scaling law in an open Friedmann universe. In a flat universe, the fluctuations are not scale-invariant. We compute the growth rate of adiabatic scale-invariant density fluctuations in flat, open…

Astrophysics · Physics 2007-05-23 Elcio Abdalla , Roya Mohayaee

The Universe on scales $10-100~h^{-1}$ Mpc is dominated by a cosmic web of voids, filaments, sheets and knots of galaxy clusters. These structures participate differently in the global expansion of the Universe: from non-expanding clusters…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-21 Krzysztof Bolejko , M. Ahsan Nazer , David L. Wiltshire

An entropic-force scenario, i.e., entropic cosmology, assumes that the horizon of the universe has an entropy and a temperature. In the present study, in order to examine entropic cosmology, we derive entropic-force terms not only from the…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-30 Nobuyoshi Komatsu , Shigeo Kimura

It was shown by Tsallis and Cirto that thermodynamical entropy of a gravitational system such as black hole must be generalized to the non-additive entropy, which is given by $S_h=\gamma A^{\beta}$, where $A$ is the horizon area and $\beta$…

General Relativity and Quantum Cosmology · Physics 2018-09-26 Ahmad Sheykhi

We show that the use of suitable theorems for black hole formation in Friedmann expanding universes leads to a modification of the Bekenstein-Hawking entropy. By adopting an argument similar to the original Bekenstein one, we write down the…

High Energy Physics - Theory · Physics 2014-05-29 Stefano Viaggiu

The general relativistic cosmological Friedmann equations which describe how the scale factor of the universe evolves are expanded explicitly to include energy forms not usually seen. The evolution of the universe as predicted by the…

Astrophysics · Physics 2008-11-26 Robert J. Nemiroff , Bijunath Patla

In this paper we give a physical explanation to the accelerated expansion of the Universe, alleviating the tension between the discrepancy of Hubble constant measurements. By the Euler Cauchy stress principle, we identify a controversy on…

General Relativity and Quantum Cosmology · Physics 2021-02-17 C. Ortiz

We calculate the expansion of the universe under the assumptions that $G$ varies in space and the radial size $r$ of the universe is very large (we call this the MOND regime of varying-$G$ gravity). The inferred asymptotic behavior turns…

General Relativity and Quantum Cosmology · Physics 2019-05-29 Dimitris M. Christodoulou , Demosthenes Kazanas

Despite impressive phenomenological successes, cosmological models are incomplete without an understanding of what happened at the big bang singularity. Maxwell electrodynamics, considered as a source of the classical Einstein field…

General Relativity and Quantum Cosmology · Physics 2017-02-17 A. Övgün

In this article, our goal is to investigate the cosmological dynamics and structure formation in a modified cosmological framework inspired by a generalized mass-to-horizon entropy relation and consistent with the Clausius relation.…

General Relativity and Quantum Cosmology · Physics 2026-04-20 Subhra Mondal , Amitava Choudhuri

We have probed a cosmological model in $f(R)$-gravity, which is a cubic equation in scalar curvature $R$. The terms arise due to nonlinear $f(R)$ function are treated as energy due to curvature inspired geometry. As a result, we find…

General Relativity and Quantum Cosmology · Physics 2023-05-03 G. K. Goswami , Rita Rani , Harshna Balhara , J. K. Singh

In this paper we solve Friedmann equations by considering a universal media as a non-perfect fluid with bulk viscosity and is described by a general "gamma law" equation of state of the form $p= (\gamma -1) \rho + \Lambda(t)$, where the…

General Physics · Physics 2016-11-04 G. S. Khadekar , Saibal Ray , X. -H. Meng

The Universe is filled with relic neutrinos, remnants from the Leptonic Era. Since the formation of galaxies started, gravitation has modified the Fermi-Dirac momentum distribution of these otherwise decoupled particles. Decelerated…

Astrophysics · Physics 2007-05-23 Richard Wigmans

Intrigued by the holographic principle, Padmanabhan recently proposed a novel idea, saying that our cosmic space is emergent as cosmic time progresses. In particular, the expansion rate of the Universe is related to the difference between…

High Energy Physics - Theory · Physics 2013-09-12 Yi Ling , Wen-Jian Pan

In this article, we study the effect of the universe accelerating expansion on the structure of the general relativistic thick disks. Hence, by applying a conformal transformation on the metric of a static disk in isotropic coordinates, we…

General Relativity and Quantum Cosmology · Physics 2019-09-04 Senobar Doostali , Alireza Mirzaee , Reza Ramezani Arani , Salman Abarghouei Nejad

The aim here is to provide a set of equations for cosmology in terms of information and thermodynamical parameters. The method we implement in order to describe the universe is a development of Padmanabhan\rq{}s approach which is based on…

General Relativity and Quantum Cosmology · Physics 2015-11-04 M. Hashemi , S. Jalalzadeh , S. Vasheghani Farahani

We reconsider the entropic-force model in which both kind of Hubble terms ${\dot H}$ and $H^{2}$ appear in the effective dark energy (DE) density affecting the evolution of the main cosmological functions, namely the scale factor,…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-16 Spyros Basilakos , Joan Sola

Padmanabhan in his paper [arxiv: 1206.4916] put forth an intriguing idea arguing that the accelerated expansion of the universse can be viewed as the emergence of cosmic space as cosmic time progresses, with the expansion triggered due to…

General Relativity and Quantum Cosmology · Physics 2018-12-26 Mahith M. , Krishna P. B. , Titus K. Mathew
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