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We investigate the cosmological consequences of a simple theory in which the electric charge $e$ is allowed to vary. The theory is locally gauge and Lorentz invariant, and satisfies general covariance. We find that in this theory the fine…

Astrophysics · Physics 2014-10-13 H. B. Sandvik , J. D. Barrow , J. Magueijo

We investigate a link between the running of the fine structure constant $\alpha$ and a time evolving scalar dark energy field. Employing a versatile parameterization for the equation of state, we exhaustively cover the space of dark energy…

Astrophysics · Physics 2009-11-10 Michael Doran

General Relativity receives quantum corrections relevant at cosmological distance scales from the conformal scalar degrees of freedom required by the trace anomaly of the quantum stress tensor in curved space. In the theory including the…

General Relativity and Quantum Cosmology · Physics 2012-09-25 Emil Mottola

Searches for spacetime variations of fundamental constants have entered an era of unprecedented precision. New, high quality quasar spectra require increasingly refined analytic methods. In this article, a continuation in a series to…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-03 John K. Webb , Chung-Chi Lee

A new phenomenological dark energy model, originally associated to the large-scale structure formation and considered as a solution to the fine-tuning and coincidence problems related to the cosmological constant, was analyzed within the…

General Relativity and Quantum Cosmology · Physics 2026-03-05 A. Kazım Çamlıbel

We discuss experiments and observations aimed at testing the possible space-time variability of fundamental physical constants, predicted by the modern theory. Specifically, we consider two of the dimensionless physical parameters which are…

Atomic Physics · Physics 2007-05-23 D. A. Varshalovich , A. Y. Potekhin , A. V. Ivanchik

We analyse the constraints obtained from new atomic clock data on the possible time variation of the fine structure `constant' and the electron-proton mass ratio and show how they are strengthened when the seasonal variation of Sun's…

Cosmology and Nongalactic Astrophysics · Physics 2010-02-25 Douglas J. Shaw , John D. Barrow

We introduce a model which allows the fine structure constant (alpha) to vary throughout space and time due to a coupling to a scalar field with a non-canonical kinetic structure. This provided a new extension of the…

General Relativity and Quantum Cosmology · Physics 2015-01-20 Alexander A. H. Graham

We report a robust constrain on the possible variation of fine-structure constant, alpha = e^2/(hbar*c), obtained using O III 4959,5007, nebular emission lines from QSOs. We find Delta-alpha/alpha=-(2.1 +/- 1.6) x 10^(-5) based on a well…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 H. Rahmani , N. Maheshwari , R. Srianand

We study the dynamical description of scalar-tensor gravity by performing the best-fit analysis for two cases of exponential and power-law form of the potential and scalar field function coupled to the curvature. The models are then tested…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Hossein Farajollahi , Amin Salehi , Mohammad Nasiri

We consider a long range scalar force that mainly couples to dark matter and unstable Standard Model states, like the muon, with tiny strength. Probing this type of force would present a challenge to observations. We point out that the…

High Energy Physics - Phenomenology · Physics 2018-12-13 Hooman Davoudiasl , Pier Paolo Giardino

Location dependence of physical parameters such as the electromagnetic fine structure constant and Newton's G produce body accelerations which violate universality of free fall rates testable with laboratory and space experiments.…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Kenneth Nordtvedt

Temporal and spatial variation of fine-structure constant $\alpha\equiv e^2/\hbar c$ in cosmology has been reported in analysis of combination Keck and VLT data. This paper studies this variation based on consideration of basic spacetime…

General Relativity and Quantum Cosmology · Physics 2015-09-02 Sze-Shiang Feng , Mu-Lin Yan

In this Reply, using E.R. Bezerra de Mello's comment, I correct calculations and results presented in Phys. Lett. B 614 (2005) 140-142 about fine structure constant in the spacetime of a cosmic string.

High Energy Physics - Theory · Physics 2009-11-11 Forough Nasseri

Comparison of quasar absorption line spectra with laboratory spectra provides a precise probe for variability of the fine structure constant, alpha, over cosmological time-scales. We constrain variation in alpha in 21 Keck/HIRES Si IV…

Astrophysics · Physics 2009-08-18 M. T. Murphy , J. K. Webb , V. V. Flambaum , J. X. Prochaska , A. M. Wolfe

We analyze different data of the variation of the fine structure constant obtained with different methods to check their consistency.We test consistency using the modified Student test and confidence intervals. We split the data sets in…

Astrophysics · Physics 2009-11-13 Susana J. Landau , Claudio Simeone

The present acceleration of the Universe strongly indicated by recent observational data can be modeled in the scope of a scalar-tensor theory of gravity. We show that it is possible to determine the structure of this theory (the scalar…

General Relativity and Quantum Cosmology · Physics 2009-10-31 B. Boisseau , G. Esposito-Farese , D. Polarski , A. A. Starobinsky

(abridged) Quasar absorption lines provide a precise test of the assumed constancy of the fundamental constants of physics. We have investigated potential changes in the fine-structure constant, alpha, and the proton-to-electron mass ratio,…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-01 Julian A. King

Crossover quintessence predicts that the time variation of fundamental couplings is substantially faster at redshift $z\approx 2$ than over the past few billion years. This could reconcile the reported time variation of the fine structure…

High Energy Physics - Phenomenology · Physics 2014-11-17 C. Wetterich

One of the topical problems of contemporary physics is a possible variability of the fundamental constants. Here we consider possible variability of two dimensionless constants which are most important for calculation of atomic and…

Atomic Physics · Physics 2016-09-08 D. A. Varshalovich , A. Y. Potekhin , A. V. Ivanchik