Limits on the time variation of the electromagnetic fine-structure constant in the low energy limit from absorption lines in the spectra of distant quasars

Srianand, R. ; Chand, H. ; Petitjean, P. ; Aracil, B. (2004) Limits on the time variation of the electromagnetic fine-structure constant in the low energy limit from absorption lines in the spectra of distant quasars Physical Review Letters, 92 (12). pp. 121302-121305. ISSN 0031-9007

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Official URL: http://prl.aps.org/abstract/PRL/v92/i12/e121302

Related URL: http://dx.doi.org/10.1103/PhysRevLett.92.121302

Abstract

Most of the successful physical theories rely on the constancy of few fundamental quantities (such as the speed of light, c, the fine-structure constant, α, the proton to electron mass ratio, μ, etc), and constraining the possible time variations of these fundamental quantities is an important step toward a complete physical theory. Time variation of α can be accurately probed using absorption lines seen in the spectra of distant quasars. Here, we present the results of a detailed many-multiplet analysis performed on a new sample of Mg ii systems observed in high quality quasar spectra obtained using the Very Large Telescope. The weighted mean value of the variation in α derived from our analysis over the redshift range 0.4 ≤ z ≤ 2.3 is Δα/α = (-0.06 ± 0.06) × 10-5. The median redshift of our sample (z≃1.55) corresponds to a look-back time of 9.7 Gyr in the most favored cosmological model today. This gives a 3σ limit, -2.5 × 10-16 yr-1 = (Δα/αΔt) ≤ +1.2 × 10-16 yr-1, for the time variation of α, that forms the strongest constraint obtained based on high redshift quasar absorption line systems.

Item Type:Article
Source:Copyright of this article belongs to The American Physical Society.
ID Code:54938
Deposited On:18 Aug 2011 07:57
Last Modified:18 May 2016 07:24

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