The spontaneous breaking of local Lorentz invariance in the early Universe,
associated with a first order phase transition at a critical time tcβ,
generates a large increase in the speed of light and a superluminary
communication of information occurs, allowing all regions in the Universe to be
causally connected. This solves the horizon problem, leads to a mechanism of
monopole suppression in cosmology and can resolve the flatness problem. After
the critical time tcβ, local Lorentz (and diffeomorphism) invariance is
restored and light travels at its presently measured speed. The kinematical and
dynamical aspects of the generation of quantum fluctuations in the
superluminary Universe are investigated. A scale invariant prediction for the
fluctuation density amplitude is obtained.Comment: Updated version (with the exception of two figures not included) of
paper published in: International Journal of Modern Physics D, Vol. 2, No. 3
(1993) 351-36