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Related papers: Varying c and Particle Horizons

200 papers

The perfect fluid in the context of a covariant variable speed of light theory proposed by J. Magueijo is studied. On the one hand the modified first law of thermodynamics together with a recipe to obtain equations of state are obtained. On…

Astrophysics · Physics 2009-12-01 Juan Racker , Pablo Sisterna , Hector Vucetich

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

We consider a hypothetical possibility of the variability of light velocity with time and position in space which is derived from two natural postulates. For the consistent consideration of such variability we generalize translational…

Astrophysics · Physics 2016-08-30 Sergey S. Stepanov

We consider the particle creation scenario in the dynamical Chern-Simons modified gravity in the presence of perfect fluid equation of state $p=(\gamma-1)\rho$. By assuming various modified entropies (Bekenstein, logarithmic, power law…

General Relativity and Quantum Cosmology · Physics 2018-10-15 Abdul Jawad , Shamaila Rani , Salman Rafique

We investigate the possibility of extending Newton's second law to the general framework of theories in which special relativity is locally valid, and in which gravitation changes the flat Galilean space-time metric into a curved metric.…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Mayeul Arminjon

We investigate the laws of thermodynamics in an accelerating universe driven by dark energy with a time-dependent equation of state. In the case we consider that the physically relevant part of the Universe is that envelopped by the…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Bin Wang , Yungui Gong , Elcio Abdalla

Several models of quantum open systems are known at present to violate, according to principles of the standard quantum theory of open systems, the second law of thermodynamics. Here, a new and rather trivial model of another type is…

Statistical Mechanics · Physics 2007-05-23 V. Capek

We investigate the validity of the generalized second law of thermodynamics, in the cosmological scenario where dark energy interacts with both dark matter and radiation. Calculating separately the entropy variation for each fluid component…

High Energy Physics - Theory · Physics 2010-07-20 Mubasher Jamil , Emmanuel N. Saridakis , M. R. Setare

Although special relativity limits the actual velocity of a particle to $c$, the velocity of light, the observed velocity need not be the same as the actual velocity as the observer is only aware of the position of a particle at the time in…

General Physics · Physics 2015-05-27 Austen Berlet , Dennis G. C. McKeon , Farrukh Chishtie , Martin Houde

This work is focused on the exploration of the thermodynamics foundations of the matter creation scenario when a generalized form of the second law of thermodynamics for this scheme is implemented. In this scenario we consider an expanding…

General Relativity and Quantum Cosmology · Physics 2024-07-23 Víctor H. Cárdenas , Miguel Cruz , Samuel Lepe

We tackle the problem of the accelerating universe by reconsidering the most general form of the metric when the speed of light is allowed to evolve with time in a homogeneous and isotropic universe. A new varying speed of light (VSL) model…

General Relativity and Quantum Cosmology · Physics 2007-07-17 Corrado Appignani

The second law of thermodynamics constitutes a fundamental principle of physics, precluding the existence of perpetual motion machines and providing a natural definition of the arrow of time. Its scope extends across virtually all areas of…

General Relativity and Quantum Cosmology · Physics 2025-10-21 Alejandro Corichi , Omar Gallegos

In earlier published work, it was proposed that light speed was larger in the early universe by 30 orders of magnitude compared to its presently observed value. This change in the speed of light is associated with a spontaneous breaking of…

Astrophysics · Physics 2007-05-23 J. W. Moffat

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

We consider f(R) modified gravity theories for describing varying speed of light in a spatially flat FRW model, and find some exact solutions. Also we examine the dynamics of this model by dynamical system method assuming a LambdaCDM…

General Relativity and Quantum Cosmology · Physics 2010-02-02 Azam Izadi , Ali Shojai

We derive conditions for rotating particle detectors to respond in a variety of bounded spacetimes and compare the results with the folklore that particle detectors do not respond in the vacuum state appropriate to their motion.…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Paul C. W. Davies , Tevian Dray , Corinne A. Manogue

New varying speed of light (VSL) theories as alternatives to the inflationary model of the universe are discussed and evidence for a varying speed of light reviewed. Work linked with VSL but primarily concerned with deriving Planck's black…

General Physics · Physics 2007-05-23 Daniel J. Farrell , J. Dunning-Davies

The holographic principle can lead to cosmological scenarios, i.e., holographic equipartition models. In this model, an extra driving term (corresponding to a time-varying cosmological term) in cosmological equations depends on an…

General Relativity and Quantum Cosmology · Physics 2019-02-25 Nobuyoshi Komatsu

The present study is motivated by the study of reference [1], where the generalized second law of thermodynamics has been investigated for a flat FRW universe for two viable models of $f(T)$ gravity. In the present work, we have considered…

General Relativity and Quantum Cosmology · Physics 2013-11-22 Rahul Ghosh , Antonio Pasqua , Surajit Chattopadhyay

The second law and the generalized second law of thermodynamics in cosmology in the framework of the modified Gauss-Bonnet theory of gravity are investigated. The conditions upon which these laws hold are derived and discussed.

General Relativity and Quantum Cosmology · Physics 2011-05-27 H. Mohseni Sadjadi