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Related papers: Thermodynamics in space-times without horizons

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In this paper we find analytical expressions for thermodynamic quantities of scalar (tensor) and vector unparticle static black holes. We also find rotating solutions to these systems and analyse their thermodynamics. First we consider the…

High Energy Physics - Theory · Physics 2018-03-28 G. Alencar , C. R. Muniz

We investigate thermodynamics of the apparent horizon in $f(R)$ gravity in the Palatini formalism with non-equilibrium and equilibrium descriptions. We demonstrate that it is more transparent to understand the horizon entropy in the…

General Relativity and Quantum Cosmology · Physics 2014-11-21 Kazuharu Bamba , Chao-Qiang Geng

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

Recently it has shown that Einstein's field equations can be rewritten into a form of the first law of thermodynamics both at event horizon of static spherically symmetric black holes and apparent horizon of Friedmann-Robertson-Walker (FRW)…

General Relativity and Quantum Cosmology · Physics 2010-10-27 M. Akbar , Rong-Gen Cai

Heat always flows from hotter to a colder temperature until thermal equilibrium be finally restored in agreement with the usual (zeroth, first and second) laws of thermodynamics. However, Tolman and Ehrenfest demonstrated that the relation…

General Relativity and Quantum Cosmology · Physics 2022-01-12 J. A. S. Lima , J. Santos

Recent observations show that our universe is accelerating by dark energy, so it is important to investigate the thermodynamical properties of it. The Undulant Universe is a model with equation of state $\omega(a)=-\cos(b\ln a)$ for dark…

Astrophysics · Physics 2010-06-18 Tian Lan , Tong-Jie Zhang , Bao-Quan Wang

The use of statistical methods to model gravitational systems is crucial to physics practice, but the extent to which thermodynamics and statistical mechanics genuinely apply to these systems is a contentious issue. This paper provides new…

History and Philosophy of Physics · Physics 2025-02-04 Lorenzo Lorenzetti

The third law of black hole dynamics states that the surface gravity (temperature) of black hole cannot be reduced to zero in finite sequence of physical interactions. We argue that the same is true when surface gravity is replaced by…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Naresh Dadhich , K. Narayan

Black holes are some of the most interesting objects in the universe. While they first arise in the complicated behavior of general relativity, the physical laws ruling their behavior are surprisingly simple. For example, one of the core…

General Relativity and Quantum Cosmology · Physics 2026-03-20 Caio César Rodrigues Evangelista , Níckolas de Aguiar Alves

In this paper we have studied electrically charged black holes in a new model of nonlinear electrodynamics introduced by Kruglov in Ref. [1]. There are two parameters for the theory and the black hole could have up to two horizons.…

General Relativity and Quantum Cosmology · Physics 2021-10-19 Leonardo Balart , Sharmanthie Fernando

The connection between gravity and thermodynamics is explored. Examining a perfect fluid in gravitational equilibrium we find that the entropy is extremal only if Einstein's equations are satisfied. Conversely, one can derive part of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 J. Oppenheim

In spherical symmetry, the gravitational potential is uniquely determined by the rotational velocity profile. Numerous galaxies exhibit a universal velocity profile from which a universal gravitational profile is inferred. When treating…

Astrophysics of Galaxies · Physics 2025-04-23 Andrés Aceña , Juan Barranco , Argelia Bernal , Ericson López

The fundamental equation of the thermodynamic system gives the relation between internal energy, entropy and volume of two adjacent equilibrium states. Taking higher dimensional charged Gauss-Bonnet black hole in de Sitter space as a…

General Relativity and Quantum Cosmology · Physics 2020-12-09 Xiong-Ying Guo , Huai-Fan Li , Li-Chun Zhang

Thermodynamics of scalar fields is investigated in three dimensional black hole backgrounds in two approaches. One is mode expansion and direct computation of the partition sum, and the other is the Euclidean path integral approach. We…

High Energy Physics - Theory · Physics 2008-11-26 Ikuo Ichinose , Yuji Satoh

Although we know that black holes are characterized by a temperature and an entropy, we do not yet have a satisfactory microscopic ``statistical mechanical'' explanation for black hole thermodynamics. I describe a new approach that…

General Relativity and Quantum Cosmology · Physics 2016-01-27 S. Carlip

Motivated by the entropy-functional formulation of emergent gravity, in which spacetime is endowed with a thermodynamic entropy that, upon extremization, yields the Einstein field equations, we reformulate the onset of a neutron star as a…

General Relativity and Quantum Cosmology · Physics 2026-03-10 Wen-Xiang Chen

Inspired by applications of gravity's rainbow in UV completion of general relativity, we investigate charged topological black holes in gravity's rainbow and show that depending on the values of different parameters, these solutions may…

High Energy Physics - Theory · Physics 2018-10-31 B. Eslam Panah

We show that there are implications on thermodynamics that come from the existence of the initial cosmic singularity. At present time this is more a conceptual change than an observable one. However at very early cosmic times there is a big…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Osvaldo M. Moreschi

The activation temperature $T$ in the de Sitter environment is twice larger than the Gibbons-Hawking temperature, related to the cosmological horizon. We consider the activation temperature as the local temperature of the de Sitter vacuum,…

General Relativity and Quantum Cosmology · Physics 2023-07-18 G. E. Volovik

There is a deep link between gravity and thermodynamics; in a precise way gravity can be derived from entanglement entropy in conformal field theories. However, this depends crucially on properties of horizons, and asymptotic symmetries of…

High Energy Physics - Theory · Physics 2025-04-30 Ian Nagle