2011/10/31 by John D. Barrow, Sean Z. W. Lip · 1 citation
Mathematics · Physics and Astronomy · #Astrophysics #Black Holes and Theoretical Physics #COSMIC cancer database #Constant (computer programming) #Cosmological constant #Cosmology #Cosmology and Gravitation Theories #Dark energy #Electron #Exponential decay #Exponential function #Fine-structure constant #Galaxies: Formation, Evolution, Phenomena #Galaxy #Generalization #Mathematical analysis #Mathematical physics #Mathematics #Omega #Physics #Quantum mechanics #Quasar #Redshift #Scalar field #Theoretical physics #Universe #astro-ph.CO #gr-qc #hep-th
paper · pdf · doi:10.1103/physrevd.85.023514
published as Phys. Rev. D 85, 023514 (2012) · 25 pages, 6 figures. Minor corrections and clarifications added. Final section on spatial variations removed so that the paper focuses exclusively on time-variation
arxiv created 2011/12/06 · openalex publication_date 2012/01/10 · arxiv updated 2012/01/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
In this paper, we formulate a generalization of the simple Bekenstein-Sandvik-Barrow-Magueijo theory of varying alpha by allowing the coupling constant \ensuremathω for the corresponding scalar field \ensuremathψ to depend on \ensuremathψ. We focus on the situation where \ensuremathω is exponential in \ensuremathψ and find the late-time behaviors that occur in matter-dominated and dark-energy dominated cosmologies. We also consider the situation when the background expansion scale factor of the Universe evolves in proportion to an arbitrary power of the cosmic time. We find the conditions under which the fine-structure ``constant'' increases with time, as in the Bekenstein-Sandvik-Barrow-Magueijo theory, and establish a cosmic no-hair behavior for accelerating universes. We also find the conditions under which the fine-structure constant can decrease with time and compare the whole family of models with astronomical data from quasar absorption spectra.