Domain wall solution inF(R)gravity and variation of the fine structure constant

The gravitational field produced by a domain wall acts as a medium with spacetime-dependent permittivity ε. Therefore, the fine structure constant α=e2/4πε 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 [Formula: see text]. 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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Fine Structure Constant, Domain Walls, and Generalized Uncertainty Principle in the Universe

International Journal of Mathematics and Mathematical Sciences ◽

10.1155/2011/543894 ◽

2011 ◽

Vol 2011 ◽

pp. 1-12

Author(s):

Luigi Tedesco

Keyword(s):

Fine Structure ◽

Hydrogen Atom ◽

Domain Wall ◽

Uncertainty Principle ◽

Ground State ◽

Domain Walls ◽

Generalized Uncertainty Principle ◽

Structure Constant ◽

Fine Structure Constant ◽

The Universe

We study the corrections to the fine structure constant from the generalized uncertainty principle in the spacetime of a domain wall. We also calculate the corrections to the standard formula to the energy of the electron in the hydrogen atom to the ground state, in the case of spacetime of a domain wall and generalized uncertainty principle. The results generalize the cases known in literature.

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New Limit on Space-Time Variations in the Proton-to-Electron Mass Ratio from Analysis of Quasar J110325-264515 Spectra

Symmetry ◽

10.3390/sym12030344 ◽

2020 ◽

Vol 12 (3) ◽

pp. 344

Author(s):

T. D. Le

Keyword(s):

Fine Structure ◽

Structure Constant ◽

Space Time ◽

Fine Structure Constant ◽

Electron Mass ◽

Mass Ratio ◽

Quasar Spectra ◽

Time Variations ◽

Using Data ◽

The Universe

Astrophysical tests of current values for dimensionless constants known on Earth, such as the fine-structure constant, α , and proton-to-electron mass ratio, μ = m p / m e , are communicated using data from high-resolution quasar spectra in different regions or epochs of the universe. The symmetry wavelengths of [Fe II] lines from redshifted quasar spectra of J110325-264515 and their corresponding values in the laboratory were combined to find a new limit on space-time variations in the proton-to-electron mass ratio, ∆ μ / μ = ( 0.096 ± 0.182 ) × 10 − 7 . The results show how the indicated astrophysical observations can further improve the accuracy and space-time variations of physics constants.

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Measurement of the running of the fine structure constant below 1 GeV with the KLOE detector

EPJ Web of Conferences ◽

10.1051/epjconf/201921802012 ◽

2019 ◽

Vol 218 ◽

pp. 02012

Author(s):

Graziano Venanzoni

Keyword(s):

Fine Structure ◽

Energy Region ◽

Direct Evidence ◽

Branching Ratio ◽

Structure Constant ◽

Fine Structure Constant ◽

Recent Measurement ◽

Single Measurement ◽

Lepton Universality ◽

Hadronic Contribution

I will report on the recent measurement of the fine structure constant below 1 GeV with the KLOE detector. It represents the first measurement of the running of α(s) in this energy region. Our results show a more than 5σ significance of the hadronic contribution to the running of α(s), which is the strongest direct evidence both in time-and space-like regions achieved in a single measurement. From a fit of the real part of Δα(s) and assuming the lepton universality the branching ratio BR(ω → µ+µ−) = (6.6 ± 1.4stat ± 1.7syst) · 10−5 has been determined

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