English
Related papers

Related papers: The generalized second law in chameleon cosmology

200 papers

Here we make an attempt to extend the idea of generalized Hawking temperature and modified Bekenstein entropy at the event horizon in a fractal universe. The modified Hawking temperature and Bekenstein entropy are considered in the…

General Relativity and Quantum Cosmology · Physics 2016-12-02 Sourav Haldar , Jibitesh Dutta , Subenoy Chakraborty

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 investigate both the ``physical process'' version of the first law and the second law of black hole thermodynamics for charged and rotating black holes. We begin by deriving general formulas for the first order variation in ADM mass and…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Sijie Gao , Robert M. Wald

The dynamics of particle, event, and apparent horizons in FLRW space are discussed. The apparent horizon is trapping when the Ricci curvature is positive. This simple criterion coincides with the condition for the Kodama-Hayward apparent…

General Relativity and Quantum Cosmology · Physics 2011-08-08 Valerio Faraoni

Based on recent data about the history of the Hubble factor, it is argued that the second law of thermodynamics holds at the largest scales accessible to observation. This is consistent with previous studies of the same question.

Cosmology and Nongalactic Astrophysics · Physics 2025-12-02 Narayan Banerjee , Purba Mukherjee , Diego Pavón

We have considered the flat FRW model of the universe which is filled with the combination of dark matter and dark energy. Here we have considered two types of dark energy models: (i) Generalized holographic and (ii) generalized Ricci dark…

General Physics · Physics 2015-05-28 Samarpita Bhattacharya , Ujjal Debnath

In this work, we have considered the Friedmann-Robertson-Walker (FRW) model of the universe where bounce occurs and the universe is filled with Generalized Cosmic Chaplygin Gas (GCCG) or Variable Modified Chaplygin Gas (VMCG). We have…

General Relativity and Quantum Cosmology · Physics 2018-12-11 Tanwi Bandyopadhyay , Ujjal Debnath

Here we consider our universe as inhomogeneous spherically symmetric Lemaitre-Tolman-Bondi Model and analyze the thermodynamics of this model of the universe. The trapping horizon is calculated and is found to coincide with the apparent…

General Relativity and Quantum Cosmology · Physics 2011-05-09 Subenoy Chakraborty , Nairwita Mazumder , Ritabrata Biswas

In this work, we study some thermodynamical aspects associated with torsion in a flat FLRW spacetime cosmic evolution. By implementing two Ansatze for the torsion term, we find that the model admits a phantom regime or a quintessence…

General Relativity and Quantum Cosmology · Physics 2020-06-26 Miguel Cruz , Fernando Izaurieta , Samuel Lepe

We review our approach to the second law of thermodynamics, viewed as a theorem asserting the growth of the mean (Gibbs-von Neumann) entropy of quantum spin systems undergoing automorphic (unitary) adiabatic transformations. Non-automorphic…

Mathematical Physics · Physics 2022-08-16 Walter F. Wreszinski

We apply methods of dynamical systems to study the behaviour of universe dominated by the generalized Chaplygin gas. We reduce the dynamics to a 2-dimensional Hamiltonian system and study its behaviour for various ranges of parameters. The…

Astrophysics · Physics 2009-11-10 Marek Szydlowski , Wojciech Czaja

The holographic bound asserts that the entropy $S$ of a system is bounded from above by a quarter of the area ${\cal A}$ of a circumscribing surface measured in Planck areas: $S\leq {\cal A}/4{\ell^2_P}$. This bound is widely regarded a…

General Relativity and Quantum Cosmology · Physics 2011-08-04 Shahar Hod

Based on the recent work [1,2], we formulate the first law and the second law of stochastic thermodynamics in the framework of general relativity. These laws are established for a charged Brownian particle moving in a heat reservoir and…

General Relativity and Quantum Cosmology · Physics 2025-01-09 Tao Wang , Yifan Cai , Long Cui , Liu Zhao

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

By applying the unified first law of thermodynamics on the apparent horizon of FRW universe, we get the entropy relation for the apparent horizon in quasi-topological gravity theory. Throughout the paper, the results of considering the…

General Relativity and Quantum Cosmology · Physics 2016-05-17 H. Moradpour , R. Dehghani

In this work, we have investigated the validity of GSL of thermodynamics in a universe (open, closed and flat) governed by Ho$\check{\text r}$ava-Lifshitz gravity. If the universe contains barotropic fluid the corresponding solutions have…

General Relativity and Quantum Cosmology · Physics 2011-07-25 Samarpita Bhattacharya , Ujjal Debnath

Motivated by the notion that the mathematics of gravity can be reproduced from a statistical requirement of maximal entropy, we study the consequence of introducing an entropic source term in the Einstein-Hilbert action. For a spatially…

General Relativity and Quantum Cosmology · Physics 2024-03-20 Soumya Chakrabarti

The thermodynamic second law in the evaporating black hole space-time is examined in the context of two-dimensional dilaton black hole. The dynamical evolution of entropy is investigated by using the analytical perturbation method and the…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Kouichirou Hirata , Yoshi Fujiwara , Jiro Soda

In this article, our goal is to investigate the cosmological dynamics and structure formation in a modified cosmological framework inspired by a generalized mass-to-horizon entropy relation and consistent with the Clausius relation.…

General Relativity and Quantum Cosmology · Physics 2026-04-20 Subhra Mondal , Amitava Choudhuri

The laws of thermodynamics, despite their wide range of applicability, are known to break down when systems are correlated with their environments. Here, we generalize thermodynamics to physical scenarios which allow presence of…

Quantum Physics · Physics 2018-02-06 Manabendra Nath Bera , Arnau Riera , Maciej Lewenstein , Andreas Winter
‹ Prev 1 8 9 10 Next ›