arXiv:astro-ph/0102144·v4·Astrophysics
Early-universe constraints on a time-varying fine structure constant
P.P. Avelino🇵🇹 · S. Esposito🇮🇹 · G. Mangano🇮🇹 · C.J.A.P. Martins🇵🇹 · A. Melchiorri🇬🇧 · G. Miele🇮🇹 · O. Pisanti🇮🇹 · G. Rocha🇵🇹 · P.T.P. Viana🇵🇹
Abstract
Higher-dimensional theories have the remarkable feature of predicting a time (and hence redshift) dependence of the `fundamental' four dimensional constants on cosmological timescales. In this paper we update the bounds on a possible variation of the fine structure constant alpha at the time of BBN (z =10^10) and CMB (z=10^3). Using the recently-released high-resolution CMB anisotropy data and the latest estimates of primordial abundances of 4He and D, we do not find evidence for a varying alpha at more than one-sigma level at either epoch.
Comments: 5 pages, 1 figure, minor misprints corrected, references added. The analysis has been updated using new BOOMERanG and DASI data on CMB anisotropy