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Related papers: Black Hole Constraints on Varying Fundamental Cons…

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Here it is shown that the variation in the fine structure constant measured by Webb et al. matches the theoretically derived value for the maximum variation in the electronic charge permitted by the Generalized Second Law of Thermodynamics…

Astrophysics · Physics 2007-05-23 Jane H MacGibbon

The theoretical maximum time variation in the electronic charge permitted by the Generalized Second Law of Thermodynamics applied to black holes radiating and accreting in the cosmic microwave background matches the measured cosmological…

General Relativity and Quantum Cosmology · Physics 2010-04-02 Jane H. MacGibbon

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

Recent astrophysical observations suggest that the value of fine structure constant $\alpha=e^2/\hbar c$ may be slowly increasing with time. This may be due to an increase of $e$ or a decrease of $c$, or both. In this article, we argue from…

High Energy Physics - Theory · Physics 2014-11-18 Saurya Das , Gabor Kunstatter

A recent paper [DDL] claims that the increase of the proton electric charge e leads to a (forbidden) decrease of black hole entropy, therefore, possible evidence for variation of $\alpha=e^2/\hbar c$ [alpha] must be interpreted as a…

Astrophysics · Physics 2007-05-23 V. V. Flambaum

Here we apply the Generalized Second Law of Thermodynamics (GSL) to black holes accreting and emitting in the present Universe and derive upper limits on the variation in the gravitational constant G. The limits depend on how the…

Astrophysics · Physics 2007-06-21 Jane H MacGibbon

Speculation that the fine-structure constant $\alpha$ varies in spacetime has a long history. We derive, in 4-D general relativity and in isotropic coordinates, the solution for a charged spherical black hole according to the framework for…

General Relativity and Quantum Cosmology · Physics 2013-11-06 Jacob D. Bekenstein , Marcelo Schiffer

New and rather controversial observations hint that the fine structure constant \alpha may have been smaller in the early universe, suggesting that some of the fundamental ``constants'' of physics may be dynamical. In a recent paper,…

High Energy Physics - Theory · Physics 2010-04-28 S. Carlip , S. Vaidya

We discuss the Flambaum commentary [arXiv:0808.2518] on the application of the Generalized Second Law of Thermodynamics to derive limits on the variation of fundamental constants, for example the fine structure constant.

General Relativity and Quantum Cosmology · Physics 2009-02-27 Jane H MacGibbon

In this paper we calculate charge fluctuations of a Schwarzschild black-hole of mass $M$ confined within a perfectly reflecting cavity of radius R in thermal equilibrium with various species of radiation and fermions . Charge conservation…

General Relativity and Quantum Cosmology · Physics 2016-08-03 Marcelo Schiffer

We study aspects of d-dimensional black holes with two electric charges, corresponding to fundamental strings with generic momentum and winding on an internal circle. The perturbative alpha' corrections to such black holes and their…

High Energy Physics - Theory · Physics 2010-02-11 Amit Giveon , Dan Gorbonos , Merav Stern

Recently it has been suggested that an increase in the fine structure constant alpha with time would decrease the entropy of a Reissner-Nordstrom black hole, thereby violating the second law of thermodynamics. In this note we point out…

High Energy Physics - Theory · Physics 2009-11-07 Malcolm Fairbairn , Michel H. G. Tytgat

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

Absorption-line systems detected in high resolution quasar spectra can be used to compare the value of dimensionless fundamental constants such as the fine-structure constant, alpha, and the proton-to-electron mass ratio, mu = m_p/m_e, as…

We summarize the attempts by our group and others to derive constraints on variations of fundamental constants over cosmic time using quasar absorption lines. Most upper limits reside in the range 0.5-1.5x10-5 at the 3sigma level over a…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Patrick Petitjean , Raghunathan Srianand , Hum Chand , Alexander Ivanchik , Pasquier Noterdaeme , Neeraj Gupta

The absorption rate of low-energy, or soft, electromagnetic radiation by spherically symmetric black holes in arbitrary dimensions is shown to be fixed by conservation of energy and large gauge transformations. We interpret this result as…

High Energy Physics - Theory · Physics 2017-04-26 Steven G. Avery , Burkhard U. W. Schwab

Many modern theories predict that the fundamental constants depend on time, position, or the local density of matter. We develop a spectroscopic method for pulsed beams of cold molecules, and use it to measure the frequencies of microwave…

Most of the successful physical theories rely on the constancy of few fundamental quantities (such as the speed of light, $c$, the fine-structure constant, \alpha, the proton to electron mass ratio, \mu, etc), and constraining the possible…

Astrophysics · Physics 2008-11-26 Raghunathan Srianand , Hum Chand , Patrick Petitjean , Bastien Aracil

We investigate the weak cosmic censorship conjecture in charged anti-de Sitter black holes with thermodynamic pressure and volume by the scattering of the charged scalar field in four and higher dimensions. We assume that the internal…

General Relativity and Quantum Cosmology · Physics 2019-08-20 Bogeun Gwak

We update the constraints on the time variation of the fine structure constant $\alpha$ and the electron mass $m_e$, using the latest CMB data, including the 7-yr release of WMAP. We made statistical analyses of the variation of each one of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Susana. J. Landau , Claudia G. Scóccola
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