Emergent Universe from Scale Invariant Two Measures Theory

TL;DR

This paper investigates a scale-invariant Two Measures Field Theory model that allows for stable emergent universe solutions, explores the transition to inflation, and analyzes density perturbations within a cosmological context.

Contribution

It introduces a novel scale-invariant TMT framework that naturally produces emergent universe solutions and studies their evolution and perturbations.

Findings

Stable emerging universe solutions identified.

Transition from emergent phase to inflation demonstrated.

Density perturbation spectrum analyzed and constrained.

Abstract

The dilaton-gravity sector of a linear in the scalar curvature, scale invariant Two Measures Field Theory (TMT), is explored in detail in the context of closed FRW cosmology and shown to allow stable emerging universe solutions. The model possesses scale invariance which is spontaneously broken due to the intrinsic features of the TMT dynamics. We study the transition from the emerging phase to inflation, and then to a zero cosmological constant phase. We also study the spectrum of density perturbations and the constraints that impose on the parameters of the theory.