Design of a Cyclic Multiverse

TL;DR

This paper proposes a cyclic multiverse model where the observable universe naturally emerges, emphasizing the importance of a prolonged dark energy phase before each cycle's turnaround to address previous challenges in cyclic universe scenarios.

Contribution

It introduces a novel cyclic multiverse design that ensures the emergence of observable universes by incorporating a long dark energy period before cycle turnaround.

Findings

A long dark energy phase is crucial for universe emergence.

The model addresses issues of scale invariance in perturbations.

It provides a consistent framework for cyclic multiverse scenarios.

Abstract

Recently, it has been noticed that the amplification of the amplitude of curvature perturbation cycle by cycle can lead to a cyclic multiverse scenario, in which the number of universes increases cycle by cycle. However, this amplification will also inevitably induce either the ultimate end of corresponding cycle, or the resulting spectrum of perturbations inside corresponding universe is not scale invariant, which baffles the existence of observable universes. In this paper, we propose a design of a cyclic multiverse, in which the observable universe can emerges naturally. The significance of a long period of dark energy before the turnaround of each cycle for this implementing is shown.