The Eternal Closed Universe: Deflation-Inflation

TL;DR

This paper proposes a model of an eternal closed universe that smoothly transitions from deflation to inflation without singularities, extending inflationary theory to include a symmetric deflation phase.

Contribution

It introduces a novel extension of inflationary models to include deflation, resulting in a non-singular, eternal closed universe within classical and semiclassical gravity frameworks.

Findings

The universe undergoes a symmetric deflation-inflation cycle.

No singularity occurs at the transition point.

The model describes an eternal universe with contracting and expanding phases.

Abstract

An outgrowth of the idea of inflation is advanced. In the inflation regime, the singularity condition is broken. Equations which govern inflation are invariant under time reversal, so that they describe deflation as well. Those two observations suggest that inflation may be extended to the following process: deflation (t<0)--minimum radius >0 (t=0)--inflation (t>0), with no singularity. A relevant construction is carried out in the framework both of classical and of reductive semiclassical gravity. The construction results in an eternal (-\infty<t<\infty) contracting-expanding closed universe.