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Related papers: Varying c and Particle Horizons

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We apply the generalized second law of thermodynamics to discriminate among quantum corrections (whether logarithmic or power-law) to the entropy of the apparent horizon in spatially Friedmann-Robertson-Walker universes. We use the…

General Relativity and Quantum Cosmology · Physics 2014-11-21 Ninfa Radicella , Diego Pavón

We consider nonstandard photons from nonbirefringent modified Maxwell theory and discuss their propagation in a fixed Schwarzschild spacetime background. This particular modification of Maxwell theory is Lorentz-violating and allows for…

High Energy Physics - Theory · Physics 2009-04-17 G. Betschart , E. Kant , F. R. Klinkhamer

In this work, we have considered that the flat FRW universe is filled with the mixture of dark matter and the new holographic dark energy. If there is an interaction, we have investigated the natures of deceleration parameter, statefinder…

General Physics · Physics 2015-05-27 Ujjal Debnath , Surajit Chattopadhyay

We shall investigate the possibility of formulation of varying speed of light (VSL) in the framework of Palatini non-linear Ricci scalar and Ricci squared theories. Different speeds of light including the causal structure constant,…

General Relativity and Quantum Cosmology · Physics 2009-11-19 Azam Izadi , Ali Shojai

The generalized second law of gravitational thermodynamics is applied to the present era of accelerated expansion of the Universe. In spite of the fact that the entropy of matter and relic gravitational waves inside the event horizon…

General Relativity and Quantum Cosmology · Physics 2009-11-11 German Izquierdo , Diego Pavon

In the Letter [1] (also [2]) there is a claim that the generalised second law of thermodynamics (entropy increase) for black holes provides some limits on the rate of variation of the fundamental constants of nature (electric charge e,…

General Relativity and Quantum Cosmology · Physics 2009-02-27 V. V. Flambaum

Cosmological models may result in future singularities. We show that, in the framework of dynamical varying speed of light theories, it is possible to regularize those singularities.

General Relativity and Quantum Cosmology · Physics 2016-01-20 F. Shojai , A. Shojai , M. Sanati

Quantum thermodynamics investigates how robust the second law of thermodynamics serves as the unique fundamental law in the small quantum world. To tackle this problem, the quantum coherence constitutes a major difficulty of investigations,…

Quantum Physics · Physics 2025-10-08 Naoto Shiraishi , Ryuji Takagi

Events in mesoscopic systems often take place at first-passage times, as is for instance the case for a colloidal particle that escapes a metastable state. An interesting question is how much work an external agent has done on a particle…

Statistical Mechanics · Physics 2020-02-05 Izaak Neri

We investigate the validity of the generalized second law of gravitational thermodynamics on the apparent and event horizons in a non-flat FRW universe containing the interacting dark energy with dark matter. We show that for the dynamical…

General Relativity and Quantum Cosmology · Physics 2011-01-18 K. Karami , S. Ghaffari , M. M. Soltanzadeh

We make the hypothesis that the velocity of light and the expansion of the universe are two aspects of one single concept connecting space and time in the expanding universe. We show that solving Friedman's equations with that…

Astrophysics · Physics 2009-06-23 J. -M. Vigoureux , P. Vigoureux , B. Vigoureux

Varying physical constant cosmologies were claimed to solve standard cosmological problems such as the horizon, the flatness and the $\Lambda$-problem. In this paper, we suggest yet another possible application of these theories: solving…

High Energy Physics - Theory · Physics 2015-06-05 Mariusz P. Dabrowski , Konrad Marosek

In this paper, we investigate the validity of the generalized second law (GSL) of thermodynamics in flat FRW chameleon cosmology where the boundary of the universe is assumed to be enclosed by the dynamical apparent horizon. It has been…

General Relativity and Quantum Cosmology · Physics 2015-05-28 H. Farajollahi , A. Salehi , F. Tayebi

The first and second laws of thermodynamics should lead to a consistent scenario for discussing the cosmological constant problem. In the present study, to establish such a thermodynamic scenario, cosmological equations in a flat…

General Relativity and Quantum Cosmology · Physics 2025-06-05 Nobuyoshi Komatsu

The Second Law of black hole thermodynamics is shown to hold for arbitrarily complicated theories of higher curvature gravity, so long as we allow only linearized perturbations to stationary black holes. Some ambiguities in Wald's Noether…

General Relativity and Quantum Cosmology · Physics 2017-07-25 Aron C. Wall

It is argued that the spatial homogeneity of the early universe need not be explained as having evolved from a previous inhomogeneous state. Rather, a homogeneous cosmic initial condition follows from the Second Law of Thermodynamics…

General Relativity and Quantum Cosmology · Physics 2018-06-21 Lucas Lolli Savi

Tentative observations and theoretical considerations have recently led to renewed interest in models of fundamental physics in which certain ``constants'' vary in time. Assuming fixed black hole mass and the standard form of the…

General Relativity and Quantum Cosmology · Physics 2010-04-28 S. Carlip

This research aims to introduce a new principle in the flat space-time geometry through the elimination of the classical idea of rest and by including a universal minimum limit of speed in the quantum world. This limit, unattainable by the…

General Relativity and Quantum Cosmology · Physics 2017-11-23 Claudio Nassif

We study different manifestations of the speed of light in theories of gravity where metric and connection are regarded as independent fields. We find that for a generic gravity theory in a frame with locally vanishing affine connection,…

General Relativity and Quantum Cosmology · Physics 2018-04-18 Azam Izadi , Shadi Sajedi Shacker , Gonzalo J. Olmo , Robi Banerjee

The generalized second law is proven for semiclassical quantum fields falling across a causal horizon, minimally coupled to general relativity. The proof is much more general than previous proofs in that it permits the quantum fields to be…

General Relativity and Quantum Cosmology · Physics 2018-10-18 Aron C. Wall