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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
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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.

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P. P. Avelino, S. Esposito, G. Mangano, C. J. A. P. Martins, A. Melchiorri, G. Miele, O. Pisanti, G. Rocha, P. T. P. Viana. 2001-06-18. Early-universe constraints on a time-varying fine structure constant. https://doi.org/10.1103/physrevd.64.103505

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