Cosmological Models with Variable “Constants”

The behavior of the “constants,” G, c, ℏ, a, e, mi, and Λ, considering them asvariable, in the framework of a flat cosmological model with FRW symmetriesdescribed by a bulk viscous fluid and considering mechanisms of adiabatic mattercreation are investigated. Two cases are studied; one with radiationpredominance and another of matter predominance. It is found that with the solution obtainedour model verifies these basic principles: Lorentz invariance and generalcovariance, Mach, Equivalence and causality. Finally, to emphasize that the envisaged modelsare free from the main problem: Planck's, horizon and entropy. With regard tothat model with matter predominance it is seen that mechanisms of creation ofmatter cannot be considered since if these are taken into account thetemperature would increase instead of remaining constant while the universe expands.