Variation of the fine-structure constant in QSO spectra from coherent dark matter oscillations

• Published in: Monthly notices of the Royal Astronomical Society 2004-04, Vol.349 (4), p.1500-1504
• Main Authors: Barnett, M. G., Dick, R., Wunderle, K. E.
• Format: Article
• Language: English
• Subjects: Astronomy; atomic data; Cosmology; cosmology: theory; dark matter; Earth, ocean, space; Exact sciences and technology; Observational cosmology (including hubble constant, distance scale, cosmological constant, early universe, etc.); Stellar systems. Galactic and extragalactic objects and systems. The universe
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1111/j.1365-2966.2004.07625.x

Abstract We consider the problem of the evolution of the fine-structure coefficient α under the assumption that the scalar field coupling to the Maxwell term satisfies the condition mt≫ 1 for coherent dark matter oscillations. In this case we find that the coupling scale f in the leading-order coupling −(φ/4f) F μν F μν affects the cosmological evolution of α according to ln(α/α0) ∝ξ(m Pl/f) × ln [tanh(t/2τ)/tanh(t 0/2τ)]. A fit to the QSO observations by Murphy et al. yields f=ξ× 2.12+0.58 −0.37× 105 m Pl. Here m Pl= (8πGN )−1/2 is the reduced Planck mass, and ξ2=ϱφ/ϱ m parametrizes the contribution of φ to the matter density in the Universe.