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26 April 2024 |
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New Limits on the Possible Variation of Physical Constants | | M. J. Drinkwater
; J. K. Webb
; J. D. Barrow
; V. V. Flambaum
; | | Date: |
25 Nov 1997 | | Subject: | astro-ph gr-qc hep-ph | | Affiliation: | University of New South Wales, University of Sussex | | Abstract: | Recent detections of high-redshift absorption by both atomic hydrogen and molecular gas in the radio spectra of quasars have provided a powerful tool to measure possible temporal and spatial variations of physical `constants’ in the Universe. We have compared the frequency of high-redshift Hydrogen 21 cm absorption with that of associated molecular absorption in two quasars to place new (1 sigma) upper limits on any variation in y = g_p.alpha^2 (where alpha is the fine structure constant and g_p is the proton g-factor) of |Delta(y)/y| < 5.10^{-6} at redshifts z=0.25 and z=0.68. These quasars are separated by a comoving distance of 3000 Mpc (H_0=75 km/s/Mpc and q_0=0). We also derive limits on the time rates of change of |(d.g_p/d.t)/g_p| < 10^{-15}/y and |(d.alpha/d.t)/alpha| < 5.10^{-16}/y between the present epoch and z=0.68. These limits are more than an order of magnitude smaller than previous results derived from high-redshift measurements. | | Source: | arXiv, astro-ph/9711290 | | Services: | Forum | Review | PDF | Favorites | |
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