ar X iv : a st ro - p h / 05 10 82 5 v 1 2 9 O ct 2 00 5 Time Variation of the Fine Structure Constant in the Spacetime of a Cosmic Domain Wall
نویسندگان
چکیده
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 /4πε will be a time-dependent function at fixed position. The most stringent constraint on the time-variation of α comes from the natural reactor Oklo and gives | ˙ α/α| < f ew × 10 −17 yr −1. This limit constrains the tension of a cosmic domain wall to be less than σ 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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ar X iv : a st ro - p h / 05 10 82 5 v 2 1 M ar 2 00 7 Time Variation of the Fine Structure Constant in the Spacetime of a Cosmic Domain Wall
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 /4πε will be a time-dependent function at fixed position. The most stringent constraint on the time-variation of α comes from the natural reactor Oklo and gives | ˙ α/α| < f ew × 10 −17 yr −1. This limit constrains the tension of a cosmic dom...
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