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Related papers: Clausius relation and Friedmann equation in FRW un…

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In an accelerated expanding universe, one can expect the existence of an event horizon. It may be interesting to study the thermodynamics of the Friedmann-Robertson-Walker (FRW) universe at the event horizon. Considering the usual Hawking…

General Relativity and Quantum Cosmology · Physics 2018-11-06 A. S. Sefiedgar , M. Mirzazadeh

The Friedmann equations of general relativity can be derived from the first law of thermodynamics when the entropy of the apparent horizon of a spatially isotropic universe is given by the Bekenstein-Hawking entropy. We point out that if…

General Relativity and Quantum Cosmology · Physics 2009-11-19 James E. Lidsey

To investigate the relationship between gravity and thermodynamics in the case of dynamic systems, we interpret the apparent horizon of the Friedmann-Lema\^itre-Robertson-Walker (FLRW) spacetime as a thermodynamic system. We derive the…

General Relativity and Quantum Cosmology · Physics 2023-03-22 Luis M. Sanchez , Hernando Quevedo

We apply the holographic principle and the equipartition law of energy to the apparent horizon of a Friedmann-Robertson-Walker universe and derive the Friedmann equation describing the dynamics of the universe. We also show that the…

General Relativity and Quantum Cosmology · Physics 2011-05-05 Fu-Wen Shu , Yungui Gong

Utilizing Kaniadakis entropy associated with the apparent horizon of the Friedmann-Robertson-Walker (FRW) Universe and applying the emergence of cosmic space paradigm, we deduce the modified Friedmann equation for a non-flat…

General Relativity and Quantum Cosmology · Physics 2024-05-08 Pranav Prasanthan , Sarath Nelleri , Navaneeth Poonthottathil , Sreejith E K

In this paper, we study thermodynamical properties of the apparent horizon in a universe governed by quasi-topological gravity. Our aim is twofold. First, by using the variational method we derive the general form of Friedmann equation in…

High Energy Physics - Theory · Physics 2015-06-16 M. H. Dehghani , A. Sheykhi , R. Dehghani

It is shown that the differential form of Friedmann equation of a FRW universe can be rewritten as a universal form $dE = TdS + WdV$ at apparent horizon, where $E$ and $V$ are the matter energy and volume inside the apparent horizon (the…

High Energy Physics - Theory · Physics 2008-11-26 M. Akbar , Rong-Gen Cai

Researches in the several decades have shown that the dynamics of gravity is closely related to thermodynamics of the horizon. In this paper, we derive the Friedmann acceleration equation based on the idea of "emergence of space" and…

General Relativity and Quantum Cosmology · Physics 2018-09-03 Fei-Quan Tu , Yi-Xin Chen , Bin Sun , You-Chang Yang

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

Recently, we have generalized the Bekenstein-Hawking entropy formula for black holes embedded in expanding Friedmann universes. In this letter, we begin the study of this new formula to obtain the first law of thermodynamics for dynamical…

High Energy Physics - Theory · Physics 2015-08-11 Stefano Viaggiu

With the usual definitions for the entropy and the temperature associated with the apparent horizon, we discuss the first law of the thermodynamics on the apparent in the general scalar-tensor theory of gravity with the kinetic term of the…

General Relativity and Quantum Cosmology · Physics 2016-03-04 Yumei Huang , Yungui Gong

The thermodynamics-gravity conjecture reveals that one can derive the gravitational field equations by using the first law of thermodynamics and vice versa. Considering the entropy associated with the horizon in the form of non-extensive…

General Relativity and Quantum Cosmology · Physics 2021-11-04 Mahnaz Asghari , Ahmad Sheykhi

We analyze the thermodynamic properties of the apparent horizon of Friedmann-Lema\^itre-Roberson-Walker (FLRW) spacetimes in Einstein-Gauss-Bonnet gravity. We use the generalized definition of entropy for gravity theories in higher…

General Relativity and Quantum Cosmology · Physics 2025-10-10 Luis M. Sánchez , Hernando Quevedo

Applying the Clausius relation, $\delta Q=TdS$, to the apparent horizon of FRW universe in brane world scenarios, we show that an explicit entropy expression associated with the apparent horizon can be obtained. On the apparent horizon, the…

High Energy Physics - Theory · Physics 2008-11-26 Rong-Gen Cai

Considering the Einstein field equations in Lyra manifold, and applying the unified first law of thermodynamics as well as the Clausius relation to the apparent horizon of FRW universe, we find the entropy of apparent horizon in Lyra…

General Relativity and Quantum Cosmology · Physics 2017-09-12 H. Moradpour , N. Sadeghnezhad , S. Ghaffari , A. Jahan

We exploit the parallel between dynamical black holes and cosmological spacetimes to describe the evolution of Friedmann-Lema\^itre-Robertson-Walker universes from the point of view of an observer in terms of the dynamics of the apparent…

General Relativity and Quantum Cosmology · Physics 2015-10-07 Pierre Binétruy , Alexis Helou

We explore thermodynamics of the apparent horizon in $f(T)$ gravity with both equilibrium and non-equilibrium descriptions. We find the same dual equilibrium/non-equilibrium formulation for $f(T)$ as for $f(R)$ gravity. In particular, we…

General Relativity and Quantum Cosmology · Physics 2015-05-30 Kazuharu Bamba , Chao-Qiang Geng

Relations between the tunneling rate and the unified first law of thermodynamics at the apparent horizon of the FRW universe are investigated. The tunneling rate arises as a consequence of the unified first law of thermodynamics in such a…

High Energy Physics - Theory · Physics 2015-05-13 Ke-Xia Jiang , San-Min Ke , Dan-Tao Peng , Jun Feng

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

In this paper we discuss the thermodynamics of the apparent horizon in $F(R)$ Ho\v{r}ava-Lifshitz gravity in equilibrium and non-equilibrium ensembles. We show that the second law of thermodynamics can be satisfied in this non relativistic…

General Relativity and Quantum Cosmology · Physics 2016-02-22 Abdul Jawad , Shamaila Rani , Davood Momeni , Faiza Gulshan , Ratbay Myrzakulov