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In this work, we have considered the Vaidya spacetime in null radiating fluid with perfect fluid in higher dimension and have found the solution for barotropic fluid. We have shown that the Einstein's field equations can be obtained from…

General Relativity and Quantum Cosmology · Physics 2012-10-04 Ujjal Debnath

We derive the modified Friedmann equation corresponding to the power-law corrected entropy-area relation $S_{\rm A}=\frac{A}{4}[1-K_{\alpha} A^{1-\frac{\alpha}{2}}]$ which is motivated by the entanglement of quantum fields in and out of the…

General Physics · Physics 2011-09-07 K. Karami , A. Abdolmaleki , N. Sahraei , S. Ghaffari

The expansion law proposed by Padmanabhan suggests that the evolution of the volume of the horizon is due to the difference between the degrees of freedom on the horizon and the degrees of freedom in the bulk enclosed by the horizon. In…

General Relativity and Quantum Cosmology · Physics 2022-11-04 Muhsinath. M , Hassan Basari V. T. , Titus K. Mathew

As soon as an interaction between holographic dark energy and dark matter is taken into account, the identification of IR cutoff with Hubble radius $H^{-1}$, in flat universe, can simultaneously drive accelerated expansion and solve the…

High Energy Physics - Theory · Physics 2010-01-06 Ahmad Sheykhi

A relativistic kinetic description for the irreversible thermodynamic process of gravitationally induced particle production is proposed in the context of an expanding Friedmann-Robertson-Walker (FRW) geometry. We show that the covariant…

General Relativity and Quantum Cosmology · Physics 2014-11-25 J. A. S. Lima , I. P. Baranov

There is an intriguing analogy between the gravitational dynamics of the horizons and thermodynamics. In case of general relativity, as well as for a wider class of Lanczos-Lovelock theories of gravity, it is possible to interpret the field…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Dawood Kothawala , Sudipta Sarkar , T. Padmanabhan

To clarify a holographic modified thermodynamic relation, the present study applies a general formulation for cosmological equations in a flat FLRW universe to the first law of thermodynamics, using the Bekenstein-Hawking entropy…

General Relativity and Quantum Cosmology · Physics 2025-01-22 Nobuyoshi Komatsu

The thermodynamic properties of loop quantum cosmology (LQC) without considering the Lorentz term were established in \cite{Zhu09}. In this paper, we extend this result to the recent proposed new model of LQC with the Lorentz term. We…

General Relativity and Quantum Cosmology · Physics 2021-11-11 Xiangdong Zhang

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

The present study is elaborated to investigate the validity of thermodynamical laws in a modified teleparallel gravity based on higher-order derivatives terms of torsion scalar. For this purpose, we consider spatially flat FRW model filled…

General Physics · Physics 2019-06-07 Saira Waheed , M. Zubair

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

A thermodynamic description of cosmological spacetimes may provide insights into the fundamentals of the cosmic evolution that remain otherwise obscure, similar to `black hole thermodynamics'. We investigate the thermodynamic properties of…

General Relativity and Quantum Cosmology · Physics 2026-03-31 Dipayan Mukherjee , Harkirat Singh Sahota , Swati Gavas

By employing the general expression of temperature $T_{h}=|\kappa|/2\pi = \frac{1}{2\pi \tilde{r}_{A}}(1-\frac{\dot{\tilde{r}}_{A}}{2H\tilde{r}_{A}})$ associated with the apparent horizon of a FRW universe and assuming a region of FRW…

General Relativity and Quantum Cosmology · Physics 2009-09-28 M. Akbar

In the saddle point approximation, the Euclidean path integral for quantum gravity closely resembles a thermodynamic partition function, with the cosmological constant $\Lambda$ playing the role of temperature and the ``density of…

General Relativity and Quantum Cosmology · Physics 2010-04-28 Steven Carlip

In this paper a study of the accelerated expansion problem of the large scale universe is presented. To derive Friedmann like equations, describing the background dynamics of the recent universe we take into account, that it is possibile to…

General Relativity and Quantum Cosmology · Physics 2017-09-20 M. Khurshudyan , As. Khurshudyan

It has been recently proposed that the interpretation of gravity as an emergent, entropic force might have nontrivial implications to cosmology. Here two approaches are investigated: in one, the Friedman equation receives entropic…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-18 Tomi S. Koivisto , David F. Mota , Miguel Zumalacarregui

We study thermodynamics of the apparent horizon in $F(R)$ gravity. In particular, we demonstrate that a $F(R)$ gravity model with realizing a crossing of the phantom divide can satisfy the second law of thermodynamics in the effective…

High Energy Physics - Theory · Physics 2009-09-28 Kazuharu Bamba , Chao-Qiang Geng

Using the Hayward-Kodama temperature for the apparent horizon, it is found that matter content in the Universe is not thermodynamically stable, and the entry to the late accelerated expansion is actually a second order phase transition. The…

General Relativity and Quantum Cosmology · Physics 2023-09-14 Tanima Duary , Narayan Banerjee , Ananda Dasgupta

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

It may be a common understanding at present that, once event horizons are in thermal equilibrium, the entropy-area law holds inevitably. However, no rigorous verification is given to such a very strong universality of the law in…

General Relativity and Quantum Cosmology · Physics 2011-09-06 Hiromi Saida