2009/07/31 by Hao Wei
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #astro-ph.CO #gr-qc #hep-th
paper · pdf · doi:10.1016/j.physletb.2009.10.086
published as Phys.Lett.B682:98-104,2009 · 12 pages, 1 table, 8 figures, revtex4; v2: discussions added, Phys. Lett. B in press; v3: published version
openalex publication_date 2009/10/31 · arxiv created 2009/11/15 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Since about ten years ago, varying α theories attracted many attentions, mainly due to the first observational evidence from the quasar absorption spectra that the fine structure ``constant'' might change with cosmological time. In this work, we investigate the cosmic evolution of α driven by the Dirac-Born-Infeld (DBI) scalar field. To be general, we consider various couplings between the DBI scalar field and the electromagnetic field. We also confront the resulting Δα/α with the observational constraints, and find that various cosmological evolution histories of Δα/α are allowed. Comparing with the case of varying α driven by quintessence, the corresponding constraints on the parameters of coupling have been relaxed, thanks to the relativistic correction of the DBI scalar field.