Constants and Variations: From Alpha to Omega
Author: Barrow J.D.
Source: Astrophysics and Space Science, Volume 283, Number 4, 2003 , pp. 645-660(16)
We review some of the history and properties of theories for the variation of the gravitation and fine structure `constants'. We highlight some general features of the cosmological models that exist in these theories with reference to recent quasar data that is consistent with time-variation in alpha since a redshift of 3.5. The behaviour of a simple class of varying-alpha cosmologies is outlined in the light of all the observational constraints. We discuss the key role played by non-zero vacuum energy and curvature in turning off the variation of constants in these theories and the issue of comparing extra-galactic and local observational data. We also show why black hole thermodynamics does not enable us to distinguish between time variations of different constants.
Document Type: Research article
Publication date: 2003-01-01