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Title: Constraining the time variation of the coupling constants from cosmic microwave background: effect of Λ{sub QCD}

Journal Article · · Journal of Cosmology and Astroparticle Physics
 [1];  [2]; ;  [3]
  1. Department of Physics, Graduate School of Science, The University of Tokyo, Tokyo 113-0033 (Japan)
  2. Department of Micro Engineering, Kyoto University, Kyoto 606-8501 (Japan)
  3. Research Center for the Early Universe (RESCEU), Graduate School of Science, The University of Tokyo, Tokyo 113-0033 (Japan)

We investigate constraints on the time variation of the fine structure constant between the recombination epoch and the present epoch, Δα/α≡(α{sub rec}−α{sub now})/α{sub now}, from cosmic microwave background (CMB) taking into account simultaneous variation of other physical constants, namely the electron mass m{sub e} and the proton mass m{sub p}. In other words, we consider the variation of Yukawa coupling and the QCD scale Λ{sub QCD} in addition to the electromagnetic coupling. We clarify which parameters can be determined from CMB temperature anisotropy in terms of singular value decomposition. Assuming a relation among variations of coupling constants governed by a single scalar field (the dilaton), the 95 % confidence level (C.L.) constraint on Δα/α is found to be −8.28 × 10{sup −3} < Δα/α < 1.81 × 10{sup −3}, which is tighter than the one obtained by considering only the change of α and m{sub e}. We also obtain the constraint on the time variation of the proton-to-electron mass ratio μ≡m{sub p}/m{sub e} to be −0.52 < Δμ/μ < 0.17 (95 % C.L.) under the same assumption. Finally, we also implement a forecast for constraints from the PLANCK survey.

OSTI ID:
22272964
Journal Information:
Journal of Cosmology and Astroparticle Physics, Vol. 2010, Issue 01; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
Country of Publication:
United States
Language:
English