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

Details Constraining the time variation of the coupling constants from cosmic microwave background: effect of Λ_{QCD} Constraining the time variation of the coupling constants from cosmic microwave background: effect of Λ_{QCD}

2009-10-05

arxiv.org/abs/0910.0742v3

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

25 pages, 4 figures; references added

Scientific paper

We investigate constraints on the time variation of the fine structure constant between the recombination epoch and the present epoch, \Delta\alpha/\alpha \equiv (\alpha_{rec} - \alpha_{now})/\alpha_{now}, from cosmic microwave background (CMB) taking into account simultaneous variation of other physical constants, namely the electron mass m_{e} and the proton mass m_{p}. In other words, we consider the variation of Yukawa coupling and the QCD scale \Lambda_{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 \Delta\alpha/\alpha is found to be -8.28 \times 10^{-3} < \Delta\alpha/\alpha < 1.81 \times 10^{-3}, which is tighter than the one obtained by considering only the change of \alpha and m_{e}. We also obtain the constraint on the time variation of the proton-to-electron mass ratio \mu \equiv m_{p}/m_{e} to be -0.52 < \Delta\mu/\mu < 0.17 (95% C.L.) under the same assumption. Finally, we also implement a forecast for constraints from the PLANCK survey.

Affiliated with

Also associated with

No associations

Rating

Constraining the time variation of the coupling constants from cosmic microwave background: effect of Λ_{QCD} does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Constraining the time variation of the coupling constants from cosmic microwave background: effect of Λ_{QCD}, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Constraining the time variation of the coupling constants from cosmic microwave background: effect of Λ_{QCD} will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-9862