Dynamical mechanism for varying light velocity as a solution to cosmological problems
Abstract
A dynamical model for varying light velocity in cosmology is developed, based on the idea that there are two metrics in spacetime. One metric g_{μν} describes the standard gravitational vacuum, and the other ĝ_{μν}=g_{μν}+βψ_{μ}ψ_{ν} describes the geometry through which matter fields propagate. Matter propagating causally with respect to ĝ_{μν} can provide acausal contributions to the matter stressenergy tensor in the field equations for g_{μν}, which, as we explicitly demonstrate with perfect fluid and scalar field matter models, provides a mechanism for the solution of the horizon, flatness and magnetic monopole problems in an FRW universe. The field equations also provide a `graceful exit' to the inflationary epoch since below an energy scale (related to the mass of ψ_{μ}) we recover exactly the standard FRW field equations.
 Publication:

Physics Letters B
 Pub Date:
 August 1999
 DOI:
 10.1016/S03702693(99)007741
 arXiv:
 arXiv:astroph/9812481
 Bibcode:
 1999PhLB..460..263C
 Keywords:

 COSMOLOGY;
 INFLATION;
 ALTERNATIVE GRAVITATIONAL THEORIES;
 CAUSALITY;
 Astrophysics;
 General Relativity and Quantum Cosmology;
 High Energy Physics  Theory
 EPrint:
 15 pages, no figures, misprint corrections. Accepted for publication in Physics Letters B