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

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The paper deals with universal thermodynamics for FRW model of the universe bounded by apparent (or event) horizon. Assuming Hawking temperature on the horizon, the unified first law is examined on the horizon for different gravity…

General Relativity and Quantum Cosmology · Physics 2016-05-17 Saugata Mitra , Subhajit Saha , Subenoy Chakraborty

The thermodynamics of the Universe is restudied by requiring its compatibility with the holographic-style gravitational equations which govern the dynamics of both the cosmological apparent horizon and the entire Universe, and possible…

General Relativity and Quantum Cosmology · Physics 2015-07-29 David Wenjie Tian , Ivan Booth

We explore the derivation of the Friedmann equations from a thermodynamic perspective, applying the unified first law of thermodynamics to the apparent horizon of a flat Friedmann-Lema\^itre-Robertson-Walker (FLRW) universe. We extend this…

General Relativity and Quantum Cosmology · Physics 2026-01-29 Víctor H. Cárdenas , Miguel Cruz , Samuel Lepe

By following the spirit of arXiv:1003.5665, we define a new Tolman temperature of Kodama observer directly related to its acceleration. We give a generalized integral form of thermodynamics relation on virtual sphere of constant $r$ in…

High Energy Physics - Theory · Physics 2010-09-21 Yi-Xin Chen , Jian-Long Li , Yong-Qiang Wang

The modified first laws of thermodynamics at the black hole horizon and the cosmological horizon of the Schwarzschild de Sitter black hole and the apparent horizon of the Friedmann-Robertson-Walker cosmology are derived by the surface…

General Relativity and Quantum Cosmology · Physics 2016-08-15 Deyou Chen , Xiaoxiong Zeng

In the present paper, we study the thermodynamics behavior of the field equations for the generalized f(T) gravity with an arbitrary coupling between matter and the torsion scalar. In this regard, we explore the verification of the first…

General Relativity and Quantum Cosmology · Physics 2017-01-17 Tahereh Azizi , Najibeh Borhani

In this paper, we investigate the thermodynamic aspects of quadratic gravity in a $D$-dimensional Friedmann-Lemaitre-Robertson-Walker (FLRW) universe. First, we derive the field equations and the effective energy-momentum tensor for…

General Relativity and Quantum Cosmology · Physics 2025-07-17 Navid Safarzadeh Ilkhchi , Amin Rezaei Akbarieh , Yaghoub Heydarzade

In the context of the teleparallel equivalent of general relativity the concept of gravitational pressure and gravitational energy-momentum arisen in a natural way. In the case of a Friedmann-Lemaitre-Robertson-Walker space FLRW we obtain…

General Relativity and Quantum Cosmology · Physics 2018-02-19 J. F. da Rocha-Neto , B. R. Morais

Inspired by the Wald-Kodama entropy $S=A/(4G_{\text{eff}})$ where $A$ is the horizon area and $G_{\text{eff}}$ is the effective gravitational coupling strength in modified gravity with field equation $R_{\mu\nu}-Rg_{\mu\nu}/2=$ $8\pi…

General Relativity and Quantum Cosmology · Physics 2015-07-14 David Wenjie Tian , Ivan Booth

Hawking radiation is an important quantum phenomenon of black hole, which is closely related to the existence of event horizon of black hole. The cosmological event horizon of de Sitter space is also of the Hawking radiation with thermal…

High Energy Physics - Theory · Physics 2009-07-24 Rong-Gen Cai , Li-Ming Cao , Ya-Peng Hu

We derive the generalized Friedmann equation governing the cosmological evolution inside the thick brane model in the presence of two curvature correction terms: a four-dimensional scalar curvature from induced gravity on the brane, and a…

High Energy Physics - Theory · Physics 2014-11-18 Shao-Feng Wu , Guo-Hong Yang , Peng-Ming Zhang

Here, we consider a flat FRW universe whose its horizon entropy meets the R\'enyi entropy of non-extensive systems. In our model, the ordinary energy-momentum conservation law is not always valid. By applying the Clausius relation as well…

General Physics · Physics 2018-01-17 H. Moradpour , Alexander Bonilla , Everton M. C. Abreu , Jorge Ananias Neto

We disclose the deep connection between the thermodynamics and gravity in a general braneworld model with curvature correction terms on the brane and in the bulk, respectively. We show that the Friedmann equations on the 3-brane embedded in…

High Energy Physics - Theory · Physics 2008-11-26 Ahmad Sheykhi , Bin Wang , Rong-Gen Cai

The analysis of phase transitions in cosmological spacetimes shows that their existence requires a time-dependent apparent horizon radius, which in turn implies an equation of state different from that of a dark energy fluid. This condition…

General Relativity and Quantum Cosmology · Physics 2026-01-09 Carlos E. Romero-Figueroa , Hernando Quevedo

We investigate the thermodynamics of a spatially flat Friedmann-Robertson-Walker (FRW) universe within the framework of Generalized Proca (GP) theory, a comprehensive vector-tensor theory. By adopting two distinct dark energy models in GP,…

General Relativity and Quantum Cosmology · Physics 2026-01-21 Aofei Sang

We study the irreversible (non-equilibrium) thermodynamics of FRW universe containing only dark energy. Using the modified entropy-area relation which is motivated from the loop quantum gravity, we calculate the entropy-corrected form of…

General Relativity and Quantum Cosmology · Physics 2010-09-14 K. Karami , Mubasher Jamil , N. Sahraei

Thermodynamic interpretations of gravity often arise from applying the Clausius relation to spacetime horizons. In modified gravity theories with higher-order equations of motion, such as f(R) and scalar-tensor gravity, this relation…

General Relativity and Quantum Cosmology · Physics 2026-04-07 Vishnu A Pai , Vishnu S Namboothiri , Titus K Mathew

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 conception of gravity as an emergent phenomenon, rooted in the thermodynamics of spacetime, offers a radical departure from its geometric description. This paper investigates the emergence of cosmic space by synthesizing two key…

General Relativity and Quantum Cosmology · Physics 2026-01-05 Ahmad Sheykhi

We derive the Friedmann-like equations in braneworld cosmology by imposing the first law of thermodynamics and Bekenstein's area-entropy formula on the apparent horizon of a Friedmann-Roberston-Walker universe in both Randall-Sundrum II…

High Energy Physics - Theory · Physics 2008-11-26 Xian-Hui Ge