New limits on the possible variation of physical constants

Drinkwater, M. J., Webb, J. K., Barrow, J. D. and Flambaum, V. V. (1998) New limits on the possible variation of physical constants. Monthly Notices of The Royal Astronomical Society, 295 2: 457-462. doi:10.1046/j.1365-8711.1998.2952457.x

Author Drinkwater, M. J.
Webb, J. K.
Barrow, J. D.
Flambaum, V. V.
Title New limits on the possible variation of physical constants
Journal name Monthly Notices of The Royal Astronomical Society   Check publisher's open access policy
ISSN 0035-8711
Publication date 1998-01-01
Sub-type Article (original research)
DOI 10.1046/j.1365-8711.1998.2952457.x
Open Access Status DOI
Volume 295
Issue 2
Start page 457
End page 462
Total pages 6
Place of publication Oxford, United Kingdom
Publisher Oxford University Press
Language eng
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 for measuring possible temporal and spatial variations of physical 'constants' in the Universe. We compare 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 x 10(-6) at redshifts z = 0.25 and 0.68. These quasars are separated by a comoving distance of 3000 Mpc (for H-0=75 km s(-1) Mpc(-1) and q(0) = 0). We also derive limits on the time rates of change of \(g) over dot (p)/(g) over dot (p)\ < 1 x 10(-15) yr(-1) and \(alpha) over dot/(a) over dot\ < 5 x 10(-16) yr(-1) between the present epoch and z = 0.68, These limits are more than an order of magnitude smaller than previous results derived from highredshift measurements.
Keyword Astronomy & Astrophysics
Ism, Atoms
Ism, Molecules
Quasars, Absorption Lines
Cosmology, Observations
Hydrogen-21 Centimeter Absorption
Fine-structure Constant
Fundamental Constants
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Unknown

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Physical Sciences Publications
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Citation counts: TR Web of Science Citation Count  Cited 97 times in Thomson Reuters Web of Science Article | Citations
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Created: Mon, 13 Aug 2007, 20:24:41 EST