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Related papers: Modified Friedmann Equations from Tsallis Entropy

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We show that modelling the universe as a pre-geometric system with emergent quantum modes, and then constructing the classical limit, we obtain a new account of space and gravity that goes beyond Newtonian gravity even in the…

General Physics · Physics 2007-09-20 Reginald T Cahill

This work comprises a study of the thermodynamic behavior of modified $f(\bar{R},\bar{T})$ gravity, which had been developed based on a non-canonical theory known as K-essence theory. In this development, we use the Dirac-Born-Infeld (DBI)…

General Relativity and Quantum Cosmology · Physics 2024-10-14 Arijit Panda , Goutam Manna , Saibal Ray , Maxim Khlopov , Praveen Kumar Dhankar

We investigate the thermodynamic and phenomenological implications of a cosmological model governed by fractional entropy applied to the apparent horizon of a flat Friedmann-Lema\^{i}tre-Robertson-Walker (FLRW) universe. By utilizing the…

General Relativity and Quantum Cosmology · Physics 2026-04-21 Miguel Cruz , Diego da Silva , Simón González , Samuel Lepe , Joel Saavedra , Manuel Gonzalez-Espinoza

In reference [1] we considered the black hole thermodynamics with the non-extensive entropy. This entropy obeys the composition rule which coincides with the composition rule in the non-extensive Tsallis-Cirto $\delta=2$ statistics. Here we…

General Relativity and Quantum Cosmology · Physics 2025-07-31 G. E. Volovik

In this paper, we present a comprehensive cosmological analysis within the framework of $f(R, \Sigma, T)$ gravity, a modified theory that incorporates nonlinear matter-geometry coupling via the inclusion of both the trace of the…

General Relativity and Quantum Cosmology · Physics 2025-11-24 S. H. Shekh , N. Myrzakulov , Anil Kumar Yadav , Anirudh Pradhan

We investigate the cosmological implications of Tsallis entropy in two widely discussed frameworks: the Cai-Kim thermodynamic derivation of the Friedman equations and the Tsallis holographic dark energy (HDE) scenario, considering both the…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-06 Pedro M. Ibarbo-Perlaza. , J. Bayron Orjuela-Quintana , Jose L. Palacios-Córdoba , César A. Valenzuela-Toledo

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

We assume the non-flat Friedmann-Robertson-Walker (FRW) Universe as a thermodynamical system. We assume the cosmological horizon as a inner trapping horizon which is treated as dynamical apparent horizon of FRW Universe. We write the…

General Relativity and Quantum Cosmology · Physics 2020-10-06 Ujjal Debnath

We study the validity of the generalized second law (GSL) of gravitational thermodynamics in a non-flat FRW universe containing the interacting in $f(T)$ gravity. We consider that the boundary of the universe to be confined by the dynamical…

General Relativity and Quantum Cosmology · Physics 2015-06-18 Ramon Herrera

Late-time cosmic acceleration has motivated the exploration of various extensions of general relativity, among which $f(Q,\mathcal{T})$ gravity, based on the non-metricity scalar $Q$ and the trace of the energy--momentum tensor…

General Relativity and Quantum Cosmology · Physics 2026-04-29 Anirudh Pradhan , A. Husain , M. Zeyauddin , S. H. Shekh

We derive the generalized Friedmann equation governing the cosmological evolution inside the thick brane model in the presence of two curvature correction terms: a four-dimensional scalar curvature from induced gravity on the brane, and a…

High Energy Physics - Theory · Physics 2014-11-18 Shao-Feng Wu , Guo-Hong Yang , Peng-Ming Zhang

Our Universe has an arrow of time. In accordance with the second law of thermodynamics, entropy has been increasing ever since the Big Bang. The fact that matter is in thermal equilibrium in the very early Universe, as indicated by the…

General Relativity and Quantum Cosmology · Physics 2020-07-30 Daniele Gregoris , Yen Chin Ong , Bin Wang

A novel idea that the cosmic acceleration can be understood from the perspective that spacetime dynamics is an emergent phenomena was proposed by T. Padmanabhan. The Friedmann equations of FRW universe can be derived from different gravity…

General Relativity and Quantum Cosmology · Physics 2014-03-04 Wen-Yuan Ai , Xian-Ru Hu , Hua Chen , Jian-Bo Deng

In the present paper, we study the thermodynamics behavior of the field equations for the generalized f(T) gravity with an arbitrary coupling between matter and the torsion scalar. In this regard, we explore the verification of the first…

General Relativity and Quantum Cosmology · Physics 2017-01-17 Tahereh Azizi , Najibeh Borhani

Recently it has shown that Einstein's field equations can be rewritten into a form of the first law of thermodynamics both at event horizon of static spherically symmetric black holes and apparent horizon of Friedmann-Robertson-Walker (FRW)…

General Relativity and Quantum Cosmology · Physics 2010-10-27 M. Akbar , Rong-Gen Cai

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 paper, we study the nonlinear electrodynamics in the framework of $f(T)$ gravity for FRW universe along with dust matter, magnetic and torsion contributions. We evaluate the equation of state and deceleration parameters to explore…

General Relativity and Quantum Cosmology · Physics 2015-06-19 M. Sharif , Shamaila Rani

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 this paper we revisit the relation between the Friedmann equations and the first law of thermodynamics. We find that the unified first law firstly proposed by Hayward to treat the "outer"trapping horizon of dynamical black hole can be…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Rong-Gen Cai , Li-Ming Cao

We present a cosmological model arising from a gravitational theory with an infinite tower of higher-order curvature invariants that can reproduce the entire evolution of the Universe: from inflation to late-time acceleration, without…

General Relativity and Quantum Cosmology · Physics 2022-02-10 Luisa G. Jaime , Gustavo Arciniega
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