Stable Emergent Universe -- A Creation without Big-Bang

TL;DR

This paper introduces a generalized gravity-matter model with two non-Riemannian volume forms, leading to an effective theory that unifies early universe inflation and dark energy, featuring a non-singular emergent universe solution.

Contribution

It develops a new class of gravity-matter models with two volume forms, resulting in an effective potential with two flat regions and a stable emergent universe solution.

Findings

Effective potential with two flat regions for inflation and dark energy

Existence of a non-singular stable emergent universe solution

Unified description of early universe and current accelerated expansion

Abstract

Based on an earlier introduced new class of generalized gravity-matter models defined in terms of two independent non-Riemannian volume forms (alternative generally covariant integration measure densities) on the space-time manifold, we derive an effective "Einstein-frame" theory featuring the following remarkable properties: (i) We obtain effective potential for the cosmological scalar field possessing two infinitely large flat regions which allows for a unified description of both early universe inflation as well as of present dark energy epoch; (ii) For a specific parameter range the model possesses a non-singular stable "emergent universe" solution which describes an initial phase of evolution that precedes the inflationary phase.