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Time Variation of the Fine Structure Constant in the Spacetime of a Domain Wall

L. Campanelli·P. Cea·L. Tedesco
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Abstract

The gravitational field produced by a domain wall acts as a medium with spacetime-dependent permittivity ε. Therefore, the fine structure constant α= e^2/4 πεwill be a time-dependent function at fixed position. The most stringent constraint on the time-variation of αcomes from the natural reactor Oklo and gives |\dotα/α| < few 10^{-17} yr^{-1}. This limit constrains the tension of a cosmic domain wall to be less than σ\lesssim 10^{-2} MeV^3, and then represents the most severe limit on the energy density of a cosmic wall stretching our Universe.

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L. Campanelli, P. Cea, L. Tedesco. 2007-03-01. Time Variation of the Fine Structure Constant in the Spacetime of a Domain Wall. https://doi.org/10.1142/s0217732307023006

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