CMB constraints on the simultaneous variation of the fine structure constant and the electron mass

The University of Tokyo, Tōkyō, Japan
Physical Review D (Impact Factor: 4.86). 07/2006; 74(2). DOI: 10.1103/PhysRevD.74.023515
Source: arXiv

ABSTRACT We study constraints on time variation of the fine structure constant α from cosmic microwave background (CMB) taking into account simultaneous change in α and the electron mass me which might be implied in unification theories. We obtain the constraints -0.097<Δα/α<0.034 at 95% C.L. using WMAP data only, and -0.042<Δα/α<0.026 combining with the constraint on the Hubble parameter by the HST Hubble Key Project. These are improved by 15% compared with constraints assuming only α varies. We discuss other relations between variations in α and me but we do not find evidence for varying α.

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