4 papers
Variations of Alpha in Space and Time
J. D. Barrow, J. Magueijo, H. B. Sandvik
We study inhomogeneous cosmological variations in the fine structure 'constant', in Friedmann universes. Inhomogeneous motions of the scalar field driving changes in displ…
The Behaviour of Varying-Alpha Cosmologies
J. D. Barrow, H. B. Sandvik, J. Magueijo
We determine the behaviour of a time-varying fine structure 'constant' during the early and late phases of universes dominated by the kinetic energy of changing , radi…
Some exact non-vacuum Bianchi VI0 and VII0 instantons
J. D. Barrow, Y. Gaspar, P. M. Saffin
We report some new exact instantons in general relativity. These solutions are Kähler and fall into the symmetry classes of Bianchi types VI0 and VII0, with matter content of a sti…
New Limits on the Possible Variation of Physical Constants
M. J. Drinkwater, J. K. Webb, J. D. Barrow +1
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 a…