Conformal Symmetry and Deflationary Gas Universe

Abstract

We describe the "deflationary" evolution from an initial de Sitter phase to a subsequent Friedmann-Lemaître-Robertson-Walker (FLRW) period as a specific non-equilibrium configuration of a self-interacting gas. The transition dynamics corresponds to a conformal, timelike symmetry of an "optical" metric, characterized by a refraction index of the cosmic medium which continously decreases from a very large initial value to unity in the FLRW phase.