English
Related papers

Related papers: Equilibrium thermodynamics in modified gravitation…

200 papers

We develop new modified cosmological scenarios by applying the first law of thermodynamics at the Universe horizon, utilizing a new entropic functional that generalizes the standard Boltzmann-Gibbs-Shannon entropy. In particular, starting…

General Relativity and Quantum Cosmology · Physics 2026-02-24 G. G. Luciano , E. N. Saridakis

We analyse the laws of thermodynamics governing the behaviour of cosmological horizons in de Sitter space and their map to a holographic description at future infinity, $\mathcal{I}^+$. In this case, the boundary can receive signals from…

High Energy Physics - Theory · Physics 2026-04-29 Indranil Dey , Kanhu Kishore Nanda , Akashdeep Roy , Deepak Kumar Sharma , Sandip P. Trivedi

Assuming that an accelerated observer with four-velocity ${\bf u}_{\rm R}$ in a curved spacetime attributes the standard Bekenstein-Hawking entropy and Unruh temperature to his "local Rindler horizon", we show that the $\rm \it change$ in…

General Relativity and Quantum Cosmology · Physics 2016-06-21 Dawood Kothawala

We consider the AdS/CFT correspondence in the hydrodynamic regime up to the second order in a derivative expansion. We demonstrate that the fluid conservation equations are equivalent to Einstein's constraint equations projected on…

High Energy Physics - Theory · Physics 2011-07-06 Adiel Meyer

The Bekenstein-Hawking entropy suggests that thermodynamics is an intrinsic ingredient of gravity. Here, we explore the idea that requirements of thermodynamic consistency could determine the gravitational entropy in other set-ups. We…

General Relativity and Quantum Cosmology · Physics 2011-12-23 Charis Anastopoulos , Ntina Savvidou

This paper explores the non-equilibrium behavior of thermodynamics at the apparent horizon of isotropic and homogeneous universe model in $f(\mathcal{G},T)$ gravity ($\mathcal{G}$ and $T$ represent the Gauss-Bonnet invariant and trace of…

General Relativity and Quantum Cosmology · Physics 2018-03-13 M. Sharif , Ayesha Ikram

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

We show that dark energy and dark matter can be described simultaneously by ordinary Einstein gravity interacting with a single scalar field provided the scalar field Lagrangian couples in a symmetric fashion to two different spacetime…

General Relativity and Quantum Cosmology · Physics 2016-11-29 Eduardo Guendelman , Emil Nissimov , Svetlana Pacheva

We propose a new theory of gravitation, in which the affine connection is the only dynamical variable describing the gravitational field. We construct the simplest dynamical Lagrangian density that is entirely composed from the connection,…

General Relativity and Quantum Cosmology · Physics 2013-12-17 Nikodem Poplawski

We study spacetime thermodynamics for non-equilibrium processes. We first generalize the formulation of spacetime thermodynamics by using an observer outside the horizon. Then we construct the entropy balance equation of spacetime…

High Energy Physics - Theory · Physics 2015-05-28 Yuki Yokokura

In his 2005 review, Gravity and the Thermodynamics of Horizons, Paddy suggested that a vacuum in thermal equilibrium with a bath of radiation should have a gradually diminishing energy. We work through the consequences of this scenario, and…

General Relativity and Quantum Cosmology · Physics 2017-05-05 Timothy Clifton , John D. Barrow

Entropic cosmology assumes several forms of entropy on the horizon of the universe, where the entropy can be considered to behave as if it were related to the exchange (the transfer) of energy. To discuss this exchangeability, the…

General Relativity and Quantum Cosmology · Physics 2016-02-19 Nobuyoshi Komatsu , Shigeo Kimura

It is well known that de Sitter(dS) black holes generally have a black hole horizon and a cosmological horizon, both of which have Hawking radiation. But the radiation temperature of the two horizons is generally different, so dS black…

High Energy Physics - Theory · Physics 2021-02-03 Yubo Ma , Yang Zhang , Lichun Zhang , Liang Wu , Ying Gao , Shuo Cao , Yu Pan

We consider FLRW cosmological models for perfect fluid (with rho as the energy density) in the frame work of the f(rho) modified theory of gravity [V. N. Tunyak, Russ. Phys. J. 21, 1221 (1978); J. R. Ray, L. L. Smalley, Phys. Rev. D. 26,…

General Physics · Physics 2011-07-05 Yaoming Shi

We study the late-time cosmological expansion of a modified teleparallel gravity model of type logarithmic type. This modified gravitational lagrangian yields a cosmological constant term and also power-law corrections to the teleparallel…

General Relativity and Quantum Cosmology · Physics 2025-10-27 Adriel O. Aquino , Euclides G. Silva

We examine the second law of thermodynamics in the context of horizon cosmology, in particular, whether the change of total entropy (i.e. the sum of the entropy for the apparent horizon and the entropy for the matter fields) proves to be…

General Relativity and Quantum Cosmology · Physics 2024-04-09 Sergei D. Odintsov , Tanmoy Paul , Soumitra SenGupta

Classical energy conditions are investigated in generic static and spherically symmetric spacetimes. In setups with nonconstant $g_{tt} g_{rr}$, the appearance of horizons can signal the violation of the null energy condition and the…

General Relativity and Quantum Cosmology · Physics 2026-04-30 Zi-Liang Wang , Emmanuele Battista

We reconcile seemingly conflicting statements in the literature about the behavior of cosmological solutions in modified theories of gravity where the Einstein-Hilbert Lagrangian for gravity is modified by the addition of a function of the…

Astrophysics · Physics 2008-11-26 Ignacy Sawicki , Wayne Hu

We investigate the validity of generalized second law of thermodynamics of a physical system comprising of newly proposed dark energy model called Ricci Gauss-Bonnet and cold dark matter enveloped by apparent horizon and event horizon in…

General Relativity and Quantum Cosmology · Physics 2018-03-12 Ayesha Iqbal , Abdul Jawad

We explore the thermodynamic analysis at the apparent horizon in the framework of Rastall theory of gravity. We take different entropies such as the Bakenstein, logarithmic corrected, power law corrected, and the Renyi entropies. We…

General Physics · Physics 2018-12-04 Kazuharu Bamba , Abdul Jawad , Salman Rafique , Hooman Moradpour