Holographic dark energy in a cyclic universe

TL;DR

This paper explores how holographic dark energy influences the cyclic universe model, showing that quantum gravity effects can induce universe bounces and turnarounds, with a focus on the evolution of dark energy across different energy regimes.

Contribution

It introduces a linking condition that connects low and high energy regimes, providing a comprehensive model of holographic dark energy in cyclic universe scenarios.

Findings

Holographic dark energy with c<1 exhibits quintom behavior.

Quantum gravity effects enable universe bounces and turnarounds.

A linking condition unifies the evolution across energy regimes.

Abstract

In this paper we study the cosmological evolution of the holographic dark energy in a cyclic universe, generalizing the model of holographic dark energy proposed by Li. The holographic dark energy with $c<1$ can realize a quintom behavior; namely, it evolves from a quintessence-like component to a phantom-like one. The holographic phantom energy density grows rapidly and dominates the late-time expanding phase, helping realize a cyclic universe scenario in which the high energy regime is modified by the effects of quantum gravity, causing a turnaround (and a bounce) of the universe. The dynamical evolution of holographic dark energy in the regimes of low energy and high energy is governed by two differential equations, respectively. It is of importance to link the two regimes for this scenario. We propose a link condition giving rise to a complete picture of holographic evolution of a cyclic universe.