English
Related papers

Related papers: A covariant entropy conjecture on cosmological dyn…

200 papers

A classical and quantum mechanical generalized second law of thermodynamics in cosmology implies constraints on the effective equation of state of the universe in the form of energy conditions, obeyed by many known cosmological solutions,…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Ram Brustein

Universal thermodynamics for FRW model of the Universe bounded by apparent/event horizon has been considered for massive gravity theory. Assuming Hawking temperature and using the unified first law of thermodynamics on the horizon, modified…

General Relativity and Quantum Cosmology · Physics 2017-02-21 Subhajit Saha , Saugata Mitra , Subenoy Chakraborty

We propose that in time dependent backgrounds the holographic principle should be replaced by the generalized second law of thermodynamics. For isotropic open and flat universes with a fixed equation of state, the generalized second law…

High Energy Physics - Theory · Physics 2009-10-31 Richard Easther , David A. Lowe

This work is to study the generalized second law (GSL) of thermodynamics in tachyon cosmology where the boundary of the universe is assumed to be enclosed by a dynamical apparent horizon. The model is constrained with the observational…

General Relativity and Quantum Cosmology · Physics 2016-06-08 H. Farajollahi , A. Ravanpak , H. Shojaie , M. Abolghasemi

We investigate the validity of the generalized second law of thermodynamics on the $(n-1)$-dimensional brane embedded in the $(n+1)$-dimensional bulk. We examine the evolution of the apparent horizon entropy extracted through relation…

High Energy Physics - Theory · Physics 2010-05-12 Ahmad Sheykhi , Bin Wang

It is established that black holes have entropy and behave as thermodynamical systems. Associating entropy to gravitational fields has not remained limited to black holes, necessitating the notion of the second law of thermodynamics in…

High Energy Physics - Theory · Physics 2026-03-26 V. R. Shajiee , M. M. Sheikh-Jabbari

We present a novel cosmological framework that unifies matter creation dynamics with thermodynamic principles. Starting with a single-component fluid characterized by a constant equation of state parameter, $\omega$, we introduce a…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-27 Víctor H. Cárdenas , Samuel Lepe

We study the generalized second law (GSL) of thermodynamics in $f(T)$ cosmology. We consider the universe as a closed bounded system filled with $n$ component fluids in the thermal equilibrium with the cosmological boundary. We use two…

General Physics · Physics 2013-02-25 Kazuharu Bamba , Mubasher Jamil , D. Momeni , Ratbay Myrzakulov

In the context of the new standard LambdaCDM cosmology we resolve conflicts in the literature regarding fundamental aspects of the expansion of the universe and cosmic horizons and we link these concepts to observational tests. We derive…

Astrophysics · Physics 2007-05-23 Tamara M. Davis

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

This paper is the second of two papers devoted to the study of the evolution of the cosmological horizons (particle and event horizons). Specifically, in this paper we consider the extremely general case of an accelerated universe with…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-28 Berta Margalef-Bentabol , Juan Margalef-Bentabol , Jordi Cepa

We construct a generally-covariant formulation of non-equilibrium thermodynamics in General Relativity. We find covariant entropic forces arising from gradients of the entropy density, and a corresponding non-conservation of the energy…

General Relativity and Quantum Cosmology · Physics 2021-10-20 Llorenc Espinosa-Portales , Juan Garcia-Bellido

We analyze spacetimes with horizons and study the thermodynamic aspects of causal horizons, suggesting that the resemblance between gravitational and thermodynamic systems has a deeper quantum mechanical origin. We find that the observer…

General Physics · Physics 2016-10-03 Eric M Howard

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

The aim of this work is to study the role of relative entropy in the thermodynamics of black holes and cosmological horizons. We adapt some recent results on the relative entropy of coherent excitations of the vacuum, to find the variation…

General Relativity and Quantum Cosmology · Physics 2023-09-06 Edoardo D'Angelo

We investigate the validity of the generalized second law of gravitational thermodynamics on the apparent and event horizons in a non-flat FRW universe containing the interacting dark energy with dark matter. We show that for the dynamical…

General Relativity and Quantum Cosmology · Physics 2011-01-18 K. Karami , S. Ghaffari , M. M. Soltanzadeh

Cosmological adiabatic particle creation results in the generation of irreversible entropy. The evolution of this entropy is examined in a flat Friedmann--Robertson--Walker universe at late times, using a dissipative model with a power-law…

General Relativity and Quantum Cosmology · Physics 2020-09-16 Nobuyoshi Komatsu

This article develops a computational framework for determining the location of boundary-covariant apparent horizons in the geometry of conformal fluid-gravity duality in arbitrary dimensions. In particular, it is shown up to second order…

High Energy Physics - Theory · Physics 2011-05-19 Ivan Booth , Michal P. Heller , Grzegorz Plewa , Michal Spalinski

Using the corrected entropy-area relation motivated by the loop quantum gravity, we investigate the validity of the generalized second law of thermodynamics in the framework of modified FRW cosmology. We consider a non-flat universe filled…

General Relativity and Quantum Cosmology · Physics 2011-04-21 K. Karami , A. Sheykhi , N. Sahraei , S. Ghaffari

We consider a spatially flat Friedmann-Lemaitre-Robertson-Walker space time and investigate the second law and the generalized second law of thermodynamics for apparent horizon in generalized modified Gauss Bonnet theory of gravity (whose…

General Relativity and Quantum Cosmology · Physics 2011-01-17 H. Mohseni Sadjadi