Varying-Alpha and K-Essence

Abstract

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 Bekenstein-Sandvik-Barrow-Magueijo model of alpha variations. The background cosmology is studied in detail using dynamical systems techniques for a scalar field of ghost condensate type. We show generically that if the kinetic terms are chosen to allow an accelerated late-time attractor for the expansion scale factor then alpha will not asymptote to a constant at late times.

14 pages, 3 figures. v2: typos corrected, references added and some additional comments. Matches published version

References in corpus (8)

• Dynamics of dark energy
• Test of the Equivalence Principle Using a Rotating Torsion Balance
• Spatial variation in the fine-structure constant -- new results from VLT/UVES
• A Matter Bounce By Means of Ghost Condensation
• No-go theorem for k-essence dark energy
• Causality and the speed of sound
• Revision of VLT/UVES constraints on a varying fine-structure constant
• Comment on "Limits on the Time Variation of the Electromagnetic Fine-Structure Constant in the Low Energy Limit from Absorption Lines in the Spectra of Distant Quasars"