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In blackhole physics, the second law of thermodynamics is generally valid whether the blackhole is a static or a non-static one. Considering the universe as a thermodynamical system the second law of blackhole dynamics extends to the…

General Relativity and Quantum Cosmology · Physics 2011-03-14 Nairwita Mazumder , Subenoy Chakraborty

By applying the unified first law of thermodynamics on the apparent horizon of FRW universe, we get the entropy relation for the apparent horizon in quasi-topological gravity theory. Throughout the paper, the results of considering the…

General Relativity and Quantum Cosmology · Physics 2016-05-17 H. Moradpour , R. Dehghani

Deviations from the area law of the horizon entropy, in the cosmological setup, are known to lead to modified Friedmann equations governing the evolution of the universe. In this work, we propose that such modifications need not be…

General Relativity and Quantum Cosmology · Physics 2026-02-19 Amir A. Khodahami , Ahmad Sheykhi

The holographic principle can lead to cosmological scenarios, i.e., holographic equipartition models. In this model, an extra driving term (corresponding to a time-varying cosmological term) in cosmological equations depends on an…

General Relativity and Quantum Cosmology · Physics 2019-02-25 Nobuyoshi Komatsu

Considering power-law for of scale factor in a flat FRW universe we reported a reconstruction scheme for $f(G)$ gravity based on QCD ghost dark energy. We reconstructed the effective equation of state parameter and observed "quintessence"…

General Relativity and Quantum Cosmology · Physics 2014-08-14 Surajit Chattopadhyay

In the realm of the Bekenstein-Hawking entropy, the thermodynamics of apparent horizon bridges with the usual FLRW (Friedmann-Lema\^{i}tre-Robertson-Walker) equation only for a special case where the matter field is given by a perfect fluid…

General Relativity and Quantum Cosmology · Physics 2022-12-14 Shin'ichi Nojiri , Sergei D. Odintsov , Tanmoy Paul

We review thermodynamic properties of modified gravity theories such as $F(R)$ gravity and $f(T)$ gravity, where $R$ is the scalar curvature and $T$ is the torsion scalar in teleparallelism. In particular, we explore the equivalence between…

General Relativity and Quantum Cosmology · Physics 2016-06-22 Kazuharu Bamba

The thermodynamics of general relativistic systems with boundary, obeying a Hamiltonian constraint in the bulk, is argued to be determined solely by the boundary quantum dynamics, and hence by the area spectrum. Assuming, for large area of…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Ashok Chatterjee , Parthasarathi Majumdar

Bekenstein has presented evidence for the existence of a universal upper bound of magnitude $2\pi R/\hbar c$ to the entropy-to-energy ratio $S/E$ of an arbitrary {\it three} dimensional system of proper radius $R$ and negligible…

General Relativity and Quantum Cosmology · Physics 2011-03-02 Shahar Hod

In this paper, we study the nonlinear electrodynamics in the framework of $f(T)$ gravity for FRW universe along with dust matter, magnetic and torsion contributions. We evaluate the equation of state and deceleration parameters to explore…

General Relativity and Quantum Cosmology · Physics 2015-06-19 M. Sharif , Shamaila Rani

We analyze different types of quantum corrections to the Cardy-Verlinde entropy formula in a Friedmann-Robertson-Walker universe and in an (anti)-de Sitter space. In all cases we show that quantum corrections can be represented by an…

High Energy Physics - Theory · Physics 2009-09-17 Shin'ichi Nojiri , Octavio Obregon , Sergei D. Odintsov , Hernando Quevedo , Mike P. Ryan

The idea of Verlinde that gravity is an entropic force caused by information changes associated with the positions of material bodies, is used in the present work for the FRW model of the Universe. Using modified Hawking temperature, the…

General Relativity and Quantum Cosmology · Physics 2016-10-31 Saugata Mitra , Subhajit Saha , Subenoy Chakraborty

We investigate the thermodynamics at the apparent horizon of the FRW universe in $f(R,T)$ theory under non-equilibrium description. The laws of thermodynamics have been discussed for two particular models of $f(R,T)$ theory. The first law…

General Relativity and Quantum Cosmology · Physics 2014-09-26 M. Sharif , M. Zubair

First and second laws of black hole thermodynamics are examined at the apparent horizon of FRW spacetime in $f(R,R_{\alpha\beta}R^{\alpha\beta} ,\phi)$ gravity, where $R$, $R_{\alpha\beta}R^{\alpha\beta}$ and $\phi$ are the Ricci scalar,…

General Relativity and Quantum Cosmology · Physics 2016-11-17 M. Zubair , Farzana Kousar , Sebastian Bahamonde

The present work deals with four alternative formulation of Bekenstein system on event horizon in $f(R)$ gravity. While thermodynamical laws holds in universe bounded by apparent horizon, these laws break down on event horizon. With…

General Relativity and Quantum Cosmology · Physics 2016-05-27 Jibitesh Dutta , Saugata Mitra , Binod Chetry

We consider a FRW universe filled by a dark energy candidate together with other possible sources which may include the baryonic and non-baryonic matters. Thereinafter, we consider a situation in which the cosmos sectors do not interact…

General Relativity and Quantum Cosmology · Physics 2015-08-24 H. Ebadi , H. Moradpour

Two well-known quantum corrections to the area law have been introduced in the literatures, namely, logarithmic and power-law corrections. Logarithmic corrections, arises from loop quantum gravity due to thermal equilibrium fluctuations and…

High Energy Physics - Theory · Physics 2012-04-06 S. H. Hendi , A. Sheykhi

Employing the thermodynamic unified first law through the thermodynamic-gravity conjecture, in this article, we derive for a FLRW universe the Friedmann equations in the framework of Gauss-Bonnet gravity theory. To do this, we project this…

General Relativity and Quantum Cosmology · Physics 2023-10-16 Joel Saavedra , Francisco Tello-Ortiz

Jacob Bekenstein's identification of black hole event horizon area with entropy proved to be a landmark in theoretical physics. In this paper we trace the subsequent development of the resulting generalized second law of thermodynamics…

Astrophysics · Physics 2014-10-13 P. C. W. Davies , Tamara M. Davis

We pointed out that the generalized second law of thermodynamics on a de Sitter universe whose energy density stochastically fluctuates due to quantum fluctuations is seemingly violated. We have shown that even in such a case, the…

General Relativity and Quantum Cosmology · Physics 2018-01-17 Naritaka Oshita