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Related papers: General Dynamics of Varying-Alpha Universes

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In this paper, we formulate a generalization of the simple Bekenstein-Sandvik-Barrow-Magueijo (BSBM) theory of varying alpha by allowing the coupling constant, \omega, for the corresponding scalar field \psi\ to depend on \psi. We focus on…

General Relativity and Quantum Cosmology · Physics 2012-01-13 John D. Barrow , Sean Z. W. Lip

We generalize the Bekenstein-Sandvik-Barrow-Magueijo (BSBM) model for the variation of the fine structure 'constant', $\alpha ,$ to include an exponential or inverse power-law self-potential for the scalar field $% \phi $ which drives the…

General Relativity and Quantum Cosmology · Physics 2012-07-04 John D. Barrow , Baojiu Li

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

Assuming a Friedmann universe which evolves with a power-law scale factor, $a=t^{n}$, we analyse the phase space of the system of equations that describes a time-varying fine structure 'constant', $\alpha$, in the…

General Relativity and Quantum Cosmology · Physics 2009-11-07 John D. Barrow , David F. Mota

We work with a class of scalar extended theory of gravity that can drive the present cosmic acceleration as well as accommodate a mild cosmic variation of the fine structure constant $\alpha$. The motivation comes from a vintage theory…

General Relativity and Quantum Cosmology · Physics 2022-04-20 Soumya Chakrabarti

We consider variation of coupling strengths and mass ratios in and beyond the Standard Model, in the light of various mechanisms of mass generation. In four-dimensional unified models, variations in charged particle thresholds, light quark…

High Energy Physics - Phenomenology · Physics 2007-05-23 Thomas Dent

We examine the evolution of a closed, homogeneous and anisotropic cosmology subject to a variation of the fine structure 'constant', \alpha, within the context of the theory introduced by Bekenstein, Sandvik, Barrow and Magueijo, which…

General Relativity and Quantum Cosmology · Physics 2015-06-15 John D. Barrow , David Sloan

In a recent paper we demonstrated how the simplest model for varying alpha may be interpreted as the effect of a dielectric material, generalized to be consistent with Lorentz invariance. Unlike normal dielectrics, such a medium cannot…

General Relativity and Quantum Cosmology · Physics 2015-09-03 John D. Barrow , Joao Magueijo

Inspired by recent claims for a varying fine structure constant, alpha, we investigate the effect of ``promoting coupling constants to variables'' upon various parameters of the standard model. We first consider a toy model: Proca's theory…

High Energy Physics - Phenomenology · Physics 2009-11-10 Dagny Kimberly , Joao Magueijo

The cosmological evolution of a quintessence-like scalar field, phi, coupled to matter and gauge fields leads to effective modifications of the coupling constants and particle masses over time. We analyze a class of models where the scalar…

Astrophysics · Physics 2009-09-15 Seokcheon Lee , Keith A. Olive , Maxim Pospelov

The cosmological implications of introducing a variation to the fine structure `constant', \alpha are examined within the context of Loop Quantum Cosmology. The evolution of \alpha is described using the model introduced by Bekenstein,…

General Relativity and Quantum Cosmology · Physics 2016-04-29 David Sloan

We investigate an interacting quintessence dark energy - dark matter scenario and its impact on structure formation by analyzing the evolution of scalar perturbations. The interaction is introduced by incorporating a non-zero source term…

General Relativity and Quantum Cosmology · Physics 2025-02-06 Anirban Chatterjee , Abhijit Bandyopadhyay , Debasish Majumdar

Using the BSBM varying-alpha theory, with dark matter dominated by magnetic energy, and the spherical collapse model for cosmological structure formation, we have studied the effects of the dark-energy equation of state and the coupling of…

Astrophysics · Physics 2009-11-10 D. F. Mota , J. D. Barrow

In this work, we consider the so-called $\Lambda(\alpha)$CDM cosmology with $\Lambda\propto\alpha^{-6}$ while the fine-structure "constant" $\alpha$ is varying. In this scenario, the accelerated expansion of the universe is driven by the…

General Relativity and Quantum Cosmology · Physics 2017-11-16 Hao Wei , Dong-Ze Xue

We have studied the Bekenstein-Sandvik-Barrow-Magueijo (BSBM) model for the spatial and temporal variations of the fine structure constant, alpha, with the aid of full N-body simulations which explicitly and self-consistently solve for the…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-04 Baojiu Li , David F. Mota , John D. Barrow

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

The cosmological evolution of an interacting scalar field model in which the scalar field interacts with dark matter, radiation, and baryon via Lorentz violation is investigated. We propose a model of interaction through the effective…

High Energy Physics - Theory · Physics 2009-09-29 Freddy P. Zen , Arianto , Bobby E. Gunara , Triyanta , A. Purwanto

We study a theory in which the electromagnetic field is disformally coupled to a scalar field, in addition to a usual non-minimal electromagnetic coupling. We show that disformal couplings modify the expression for the fine-structure…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-16 Carsten van de Bruck , Jurgen Mifsud , Nelson J. Nunes

We consider variations of coupling strengths and mass ratios in and beyond the Standard Model, in the light of various mechanisms of mass generation. In four-dimensional unified models, heavy quark and superparticle thresholds and the…

High Energy Physics - Phenomenology · Physics 2015-06-25 Thomas Dent

A general model for the cosmological evolution of the fine structure constant \alpha driven by a typical Quintessence scenario is presented. We consider a coupling between the Quintessence scalar \phi and the electromagnetic kinetic term…

Astrophysics · Physics 2014-10-13 Valerio Marra , Francesca Rosati
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