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Related papers: The generalized second law in universes with quant…

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This work presents a universal and revisited formalism for the entropy of the apparent horizon in modified gravity to investigate the validity of the Generalized Second Law (GSL) of thermodynamics. This revisited horizon entropy is…

General Relativity and Quantum Cosmology · Physics 2025-12-22 Soma Heydari , Parastoo Askari , Kayoomars Karami

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

The paper deals with universal thermodynamics for FRW model of the universe bounded by apparent (or event) horizon. Assuming Hawking temperature on the horizon, the unified first law is examined on the horizon for different gravity…

General Relativity and Quantum Cosmology · Physics 2016-05-17 Saugata Mitra , Subhajit Saha , Subenoy Chakraborty

In this paper, we study thermodynamical properties of the apparent horizon in a universe governed by quasi-topological gravity. Our aim is twofold. First, by using the variational method we derive the general form of Friedmann equation in…

High Energy Physics - Theory · Physics 2015-06-16 M. H. Dehghani , A. Sheykhi , R. Dehghani

We give a short review of the recent developments of entropic cosmology based on two thermodynamic laws of the apparent horizon, namely the first and the second laws of thermodynamics. The first law essentially provides the change of the…

General Relativity and Quantum Cosmology · Physics 2024-09-04 Shin'ichi Nojiri , Sergei D. Odintsov , Tanmoy Paul

An equilibrium picture of thermodynamics is discussed at the apparent horizon of FRW universe in $f(T,T_G)$ gravity, where $T$ represents the torsion invariant and $T_G$ is the teleparallel equivalent of the Gauss-Bonnet term. It is found…

General Relativity and Quantum Cosmology · Physics 2015-11-04 M. Zubair

We investigate the first law of thermodynamics and entropy associated to the apparent horizon of (non-flat) FLRW space-time in different theories of modified gravity and in the presence of a perfect fluid of matter. We pose our attention on…

General Relativity and Quantum Cosmology · Physics 2023-11-21 Lorenzo Sebastiani

The Friedmann equations of general relativity can be derived from the first law of thermodynamics when the entropy of the apparent horizon of a spatially isotropic universe is given by the Bekenstein-Hawking entropy. We point out that if…

General Relativity and Quantum Cosmology · Physics 2009-11-19 James E. Lidsey

We investigate the thermodynamical properties of the apparent horizon in a fractal universe. We find that one can always rewrite the Friedmann equation of the fractal universe in the form of the entropy balance relation $ \delta Q=T_h…

General Physics · Physics 2015-06-12 Ahmad Sheykhi , Zeinab Teimoori , Bin Wang

In the framework of Fractional Action Cosmology (FAC), we study the generalized second law of thermodynamics for the Friedmann Universe enclosed by a boundary. We use the four well-known cosmic horizons as boundaries namely, apparent…

General Physics · Physics 2012-02-14 Ujjal Debnath , Mubasher Jamil , Surajit Chattopadhyay

The Generalized First Law (GFL) and the Generalized Second Law (GSL) of thermodynamics are searched for effective and alternative cosmic models using the entropy as a function of the apparent area, transforming the effective cosmological…

General Relativity and Quantum Cosmology · Physics 2025-05-15 Alejandro Corichi , Omar Gallegos

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

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

We investigate the validity of the generalized second law of gravitational thermodynamics in a non-flat FRW universe containing the interacting new agegraphic dark energy with cold dark matter. The boundary of the universe is assumed to be…

General Relativity and Quantum Cosmology · Physics 2011-04-20 K. Karami , A. Abdolmaleki

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

The influence of the generalized uncertainty principle (GUP) and extended uncertainty principle (EUP) on the thermodynamics of the Friedmann-Robertson-Walker (FRW) universe has been investigated. It is shown that the entropy of the apparent…

High Energy Physics - Theory · Physics 2009-04-06 Tao Zhu , Ji-Rong Ren , Ming-Fan Li

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

This study is conducted to examine the validity of generalized second law of thermodynamics (GSLT) in flat FRW for modified teleparallel gravity involving coupling between a scalar field with the torsion scalar $T$ and the boundary term…

General Relativity and Quantum Cosmology · Physics 2017-07-19 M. Zubair , Sebastian Bahamonde , Mubasher Jamil

We explore the derivation of the Friedmann equations from a thermodynamic perspective, applying the unified first law of thermodynamics to the apparent horizon of a flat Friedmann-Lema\^itre-Robertson-Walker (FLRW) universe. We extend this…

General Relativity and Quantum Cosmology · Physics 2026-01-29 Víctor H. Cárdenas , Miguel Cruz , Samuel Lepe