Bouncing Anisotropic Universes with Varying Constants

Abstract

We examine the evolution of a closed, homogeneous and anisotropic cosmology subject to a variation of the fine structure 'constant', α, within the context of the theory introduced by Bekenstein, Sandvik, Barrow and Magueijo, which generalises Maxwell's equations and general relativity. The variation of αpermits an effective ghost scalar field, whose negative energy density becomes dominant at small length scales, leading to a bouncing cosmology. A thermodynamically motivated coupling which describes energy exchange between the effective ghost field and the radiation field leads to an expanding, isotropizing sequence of bounces. In the absence of entropy production we also find solutions with stable anisotropic oscillations around a static universe.

9 pages, 5 figures

References in corpus (5)

• Limits on the dependence of the fine-structure constant on gravitational potential from white-dwarf spectra
• Inflation with a Negative Cosmological Constant
• The Ups and Downs of Cyclic Universes
• Wiggles in the cosmic microwave background radiation: echoes from non-singular cyclic-inflation
• Bouncing and cyclic string gas cosmologies

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• Bouncing Universes in Scalar-Tensor Gravity Models admitting Negative Potentials
• Qualitative study of anisotropic Rastall cosmologies
• Cyclic Mixmaster Universes
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• Current observations with a decaying cosmological constant allow for chaotic cyclic cosmology
• Exploring eternal stability with the simple harmonic universe
• Bouncing Universes in Scalar-Tensor Gravity Around Conformal Invariance
• Scalar Field Cosmologies With Inverted Potentials
• Evolution of initially contracting Bianchi Class A models in the presence of an ultra-stiff anisotropic pressure fluid
• Loop Quantum Cosmology and the Fine Structure Constant