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In this paper, the generalized second law (GSL) of thermodynamics and entropy is revisited in the context of cosmological models in Gauss-Bonnet gravity with the boundary of the universe is assumed to be enclosed by the dynamical apparent…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Hossein Farajollahi , Amin Salehi

In this work we have investigated the effects of three nongaussian entropies, namely, the modified R\'enyi entropy (MRE), the Sharma-Mittal entropy (SME) and the dual Kaniadakis entropy (DKE) in the investigation of the generalized second…

General Relativity and Quantum Cosmology · Physics 2022-01-05 Everton M. C. Abreu , Jorge Ananias Neto

In relativistic gravity, requiring a spacetime hypersurface be a Killing horizon breaks the general covariance of general relativity. The residual algebra of horizon preserving diffeomorphisms can be extended to a Virasoro algebra near the…

General Relativity and Quantum Cosmology · Physics 2018-10-26 David Mattingly , Matthew Roberson , Sayandeb Basu

The present study is aimed at investigating the validity of the generalized second law (GSL) of thermodynamics in $f(\cal R)$ gravity. Choosing $f(\cal R)=R+\xi R^{\mu}+\zeta R^{-\nu}$ [following Phys Rev D, 68, 123512 (2003)] we have…

General Physics · Physics 2012-11-30 Rahul Ghosh , Surajit Chattopadhyay

In this article we consider the second law of black holes (and other causal horizons) in theories where the gravitational action is an arbitrary function of the Lovelock densities. We show that there exists an entropy which increases…

General Relativity and Quantum Cosmology · Physics 2015-05-21 Sudipta Sarkar , Aron C. Wall

Within the context of scalar-tensor gravity, we explore the generalized second law (GSL) of gravitational thermodynamics. We extend the action of ordinary scalar-tensor gravity theory to the case in which there is a non-minimal coupling…

General Relativity and Quantum Cosmology · Physics 2014-05-27 A. Abdolmaleki , T. Najafi , K. Karami

Based on the entropy-area relation from Nouicer's generalised uncertainty principle (GUP), we derive the GUP modified Friedmann equations from the first law of thermodynamics at apparent horizon. We find a minimum apparent horizon due to…

General Relativity and Quantum Cosmology · Physics 2024-04-30 Özgür Ökcü

The generalized second law can be used to prove a singularity theorem, by generalizing the notion of a trapped surface to quantum situations. Like Penrose's original singularity theorem, it implies that spacetime is null geodesically…

General Relativity and Quantum Cosmology · Physics 2016-12-07 Aron C. Wall

It has been conjectured that black hole interacting with its surroundings will obey the Generalized Second Law ($GSL$) of thermodynamics. Conservation of $GSL$ is due to the fully thermal nature of Hawking radiation and an upper bound on…

General Relativity and Quantum Cosmology · Physics 2008-06-16 P. I. Kuriakose , V. C. Kuriakose

We investigate the validity of the generalized second law of thermodynamics in a universe governed by Horava-Lifshitz gravity. Under the equilibrium assumption, that is in the late-time cosmological regime, we calculate separately the…

High Energy Physics - Theory · Physics 2011-03-28 Mubasher Jamil , Emmanuel N. Saridakis , M. R. Setare

It was recently shown that the von Neumann algebras of observables dressed to the mass of a Schwarzschild-AdS black hole or an observer in de Sitter are Type II, and thus admit well-defined traces. The von Neumann entropies of…

High Energy Physics - Theory · Physics 2025-01-17 Jonah Kudler-Flam , Samuel Leutheusser , Gautam Satishchandran

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

The present work deals with a detailed study of universal thermodynamics in different modified gravity theories. The validity of the generalized second law of thermodynamics (GSLT) and thermodynamical equilibrium (TE) of the Universe…

General Relativity and Quantum Cosmology · Physics 2016-11-02 Saugata Mitra , Subhajit Saha , Subenoy Chakraborty

Based on the fractional black hole entropy (Jalalzadeh S. et al., Eur. Phys. J. C, 81 (2021) 632), we derive the modified Friedmann equations from two different frameworks. First, we consider the modifications of Friedmann equations from…

General Relativity and Quantum Cosmology · Physics 2023-09-06 Zeynep Çoker , Özgür Ökcü , Ekrem Aydiner

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

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

The generalized second law (GSL) of black hole thermodynamics states that the sum of changes in black hole entropy and the ordinary entropy of matter and fields outside the hole must be non-negative. In the classical limit, the GSL reduces…

General Relativity and Quantum Cosmology · Physics 2013-05-28 Christopher Eling , Jacob D. Bekenstein

We construct a deformed algebraic quantum field theory on bifurcate Killing horizons in stationary axisymmetric spacetimes. The deformation is generated by the commuting actions of affine dilations along the null generators of the horizon…

High Energy Physics - Theory · Physics 2026-03-16 Philipp Dorau , Albert Much , Rainer Verch

In black hole physics, the second law of thermodynamics is generally valid whether the black hole is a static or a non-static one. Considering the universe as a thermodynamical system the second law of black hole dynamics extends to the…

General Relativity and Quantum Cosmology · Physics 2010-11-19 Subenoy Chakraborty , Nairwita Mazumder , Ritabrata Biswas

We consider quantum algebras of observables associated with subregions in theories of Einstein gravity coupled to matter in the $G_N\rightarrow 0$ limit. When the subregion is spatially compact or encompasses an asymptotic boundary, we…

High Energy Physics - Theory · Physics 2024-02-07 Kristan Jensen , Jonathan Sorce , Antony Speranza