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Related papers: New Constraints on Varying Alpha

200 papers

Motivated by future gravitational waves observations, we perform forecasts analysis to constrain a possible time variation of the fine structure constant ($\alpha$) within the context of the so-called runaway dilaton model. For this…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-20 L. R. Colaço , R. F. L. Holanda , Rafael C. Nunes , J. E. Gonzalez

If the recent observations suggesting a time variation of the fine structure constant are correct, they imply the existence of an ultra light scalar particle. This particle inevitably couples to nucleons through the \alpha-dependence of…

High Energy Physics - Phenomenology · Physics 2009-11-07 Gia Dvali , Matias Zaldarriaga

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

Current analyses of VLT/UVES quasar spectra disagree with the Keck/HIRES evidence for a varying fine-structure constant, alpha. To investigate this we introduce a simple method for calculating the minimum possible uncertainty on…

Astrophysics · Physics 2015-06-24 M. T. Murphy , J. K. Webb , V. V. Flambaum

A numerical coincidence relating the values of the cosmological, gravitational and electromagnetic fine structure constants is presented and discussed in relation to the apparent anthropic fine-tuning of these three fundamental constants of…

General Relativity and Quantum Cosmology · Physics 2015-10-26 Laurence Eaves

We determine the behaviour of a time-varying fine structure 'constant' $\alpha (t)$ during the early and late phases of universes dominated by the kinetic energy of changing $\alpha (t)$, radiation, dust, curvature, and lambda,…

Astrophysics · Physics 2008-11-26 J. D. Barrow , H. B. Sandvik , J. Magueijo

Contemporary multidimensional cosmological theories predict different variations of fundamental physical constants in course of the cosmological evolution. On the basis of the QSO spectra analysis, we show that the fine-structure constant…

Astrophysics · Physics 2007-05-23 D. A. Varshalovich , A. Y. Potekhin , A. V. Ivanchik , V. E. Panchuk , K. M. Lanzetta

There are obvious discrepancies among various experimental constraints on the variation of the fine-structure constant, $\alpha$. We attempt to discuss the issue in the framework of de Sitter invariant Special Relativity (${\cal SR}_{c,R}$)…

Astrophysics · Physics 2015-06-24 Shao-Xia Chen , Neng-Chao Xiao , Mu-Lin Yan

Varying fundamental constants (VFC) [e.g., the fine-structure constant, $\alpha_{\rm EM}$] can arise in numerous extended cosmologies. Through their effect on the decoupling of baryons and photons during last scattering and reionisation,…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-13 Luke Hart , Jens Chluba

We calculate bounds on the variation of the fine structure constant at the time of primordial nucleosynthesis and at the time of neutral hydrogen formation. We use these bounds and other bounds from the late universe to test Bekenstein…

Astrophysical tests of the stability of fundamental couplings, such as the fine-structure constant $\alpha$, are a powerful probe of new physics. Recently these measurements, combined with local atomic clock tests and Type Ia supernova and…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-13 C. J. A. P. Martins , A. M. M. Pinho , P. Carreira , A. Gusart , J. López , C. I. S. A. Rocha

We study the space-time evolution of the fine structure constant, $\alpha$, inside evolving spherical overdensities in a lambda-CDM Friedmann universe using the spherical infall model. We show that its value inside virialised regions will…

Astrophysics · Physics 2011-05-05 D. F. Mota , J. D. Barrow

Recently, white dwarf stars have found a new use in the fundamental physics community. Many prospective theories of the fundamental interactions of Nature allow traditional constants, like the fine structure constant $\alpha$, to vary in…

Solar and Stellar Astrophysics · Physics 2014-10-14 S. P. Preval , M. A. Barstow , J. B. Holberg , J. D. Barrow , J. C. Berengut , J. K. Webb , D. Dougan , J. Hu

Higher-dimensional theories have the remarkable feature of predicting a time (and hence redshift) dependence of the `fundamental' four dimensional constants on cosmological timescales. In this paper we update the bounds on a possible…

It is considered that quasars evolve into normal galaxies by means of expansion of matter. The order of magnitude of the expansion velocity can be estimated. The Doppler shift caused by such expansion explains the supposed variation of the…

Astrophysics · Physics 2007-05-23 Mario Everaldo de Souza

We discuss present and future cosmological constraints on variations of the fine structure constant $\alpha$ induced by an early dark energy component having the simplest allowed (linear) coupling to electromagnetism. We find that current…

Cosmology and Nongalactic Astrophysics · Physics 2011-08-08 Erminia Calabrese , Eloisa Menegoni , C. J. A. P. Martins , Alessandro Melchiorri , Graca Rocha

We forecast the ability of future CMB and galaxy lensing surveys to constrain variations of the fine structure constant. We found that lensing data, as those expected from satellite experiments as Euclid could improve the constraint from…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Matteo Martinelli , Eloisa Menegoni , Alessandro Melchiorri

We present a short review of the current quasar (QSO) absorption line constraints on possible variation of the fine structure constant, alpha = e^2/(hbar*c). Particular attention is paid to recent optical Keck/HIRES spectra of 49 absorption…

Astrophysics · Physics 2009-08-18 M. T. Murphy , J. K. Webb , V. V. Flambaum , S. J. Curran

Cosmology contributes a good deal to the investigation of variation of fundamental physical constants. High resolution data is available and allows for detailed analysis over cosmological distances and a multitude of methods were developed.…

Cosmology and Nongalactic Astrophysics · Physics 2009-10-28 M. Wendt , D. Reimers , P. Molaro

The fine structure constant, alpha, is shown to be proportional to the ratio of the quanta of electric and magnetic flux of force of the electron, and provides a new representation, which is global across all unit systems. Consequently, a…

High Energy Physics - Phenomenology · Physics 2023-03-14 Michael Edmund Tobar