The finestructure constant: a new observational limit on its cosmological variation and some theoretical consequences
Abstract
Endeavours of the unification of the four fundamental interactions have resulted in a development of theories having cosmological solutions in which lowenergy limits of fundamental physical constants vary with time. The validity of such theoretical models should be checked by comparison of the theoretical predictions with observational and experimental bounds on possible timedependences of the fundamental constants. Based on highresolution measurements of quasar spectra, we obtain the following direct limits on the average rate of the cosmological time variation of the finestructure constant alpha : \dot{\alpha}/\alpha < 1.9 x 10^{14}yr^{1} is the most likely limit, and \dot{\alpha}/\alpha  < 3.1 x 10^{14}yr^{1} is the most conservative limit. Analogous estimates published previously, as well as other contemporary tests for possible variations of alpha (those based on the ``Oklo phenomenon'', on the primordial nucleosynthesis models, and others) are discussed and compared with the present upper limit. We argue that the present result is the most conservative one.
 Publication:

Astronomy and Astrophysics
 Pub Date:
 March 1999
 arXiv:
 arXiv:astroph/9810166
 Bibcode:
 1999A&A...343..439I
 Keywords:

 COSMOLOGY: THEORY;
 GALAXIES: QUASARS: ABSORPTION LINES;
 Astrophysics
 EPrint:
 8 pages, 2 embedded figures, 1 table, LaTeX using laa.sty and epsfig. Accepted for publication in A&