Bouncing anisotropic universes with varying constants

Barrow, John D. and Sloan, David (2013) Bouncing anisotropic universes with varying constants. Physical Review D: 023518. ISSN 1550-7998

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 and Sandvik et al. which generalizes Maxwell’s equations and general relativity The variation of α permits an effective ghost scalar field, whose negative energy density becomes dominant at small length scales, leading to a bouncing cosmology. A thermodynamically motivated coupling that 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.