# Varying alpha in a more realistic Universe

@article{Mota2004VaryingAI, title={Varying alpha in a more realistic Universe}, author={David F. Mota and John D. Barrow}, journal={Physics Letters B}, year={2004}, volume={581}, pages={141-146} }

Abstract We study the space–time evolution of the fine structure constant, α , inside evolving spherical overdensities in a lambda-CDM Friedmann universe using the spherical infall model. We show that its value inside virialised regions will be significantly larger than in the low-density background universe. The consideration of the inhomogeneous evolution of the universe is therefore essential for a correct comparison of extragalactic and solar system limits on, and observations of, possible…

## 163 Citations

Variations of the Fine Structure Constant in Space and Time

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- 2006

This thesis describes a detailed investigation of the effects of matter inhomogeneities on the cosmological evolution of the fine structure constant using the Bekenstein-Sandvik-Barrow-Magueijo…

Cosmological evolution of alpha driven by a general coupling with quintessence

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- 2005

A general model for the cosmological evolution of the fine structure constant α driven by a typical quintessence scenario is presented. We consider a coupling between the quintessence scalar and the…

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- 2012

In this work we investigate the utility of using SNe Ia observations in constraining the cosmological parameters in BSBM theory where a scalar field is responsible for both fine structure constant…

Varying alpha driven by the Dirac–Born–Infeld scalar field

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- 2009

Abstract Since about ten years ago, varying α theories attracted many attentions, mainly due to the first observational evidence from the quasar absorption spectra that the fine structure “constant”…

Varying alpha and cosmic acceleration in Brans-Dicke-BSBM theory: stability analysis and observational tests

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- 2012

By integration of generalized BSBM and Brans-Dicke cosmological models, in this article, we investigate the theoretical framework of fine structure constant variation and current cosmic acceleration.…

Evolution of the fine-structure constant in the non-linear regime

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- 2006

We study the evolution of the fine-structure constant, α, induced by non-linear density perturbations in the context of the simplest class of quintessence models with a non-minimal coupling to the…

Cosmological constants and variations

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- 2005

We review properties of theories for the variation of the gravitation and fine structure 'constants'. We highlight some general features of the cosmological models that exist in these theories with…

Local and global variations of the fine-structure constant

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Using the Bekenstein-Sandvik-Barrow-Magueijo (BSBM) varying-a theory, with dark matter dominated by magnetic energy, and the spherical collapse model for cosmological structure formation, we have…

Models of f(R) Cosmic Acceleration that Evade Solar-System Tests

- Physics
- 2007

We study a class of metric-variation fRmodels that accelerates the expansion without a cosmological constant and satisfies both cosmological and solar-system tests in the small-field limit of the…

Observational Constraints on Varying Alpha in Λ(α) CDM Cosmology

- Physics
- 2017

In this work, we consider the so-called Λ(α)CDM cosmology with Λ ∝ α while the fine-structure “constant” α is varying. In this scenario, the accelerated expansion of the universe is driven by the…

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