Emergent dark energy from unparticles

TL;DR

This paper proposes a model where unparticles induce emergent dark energy, leading to a deSitter phase that closely mimics ΛCDM, addressing key cosmological problems naturally without scalar fields or modified gravity.

Contribution

It introduces a novel cosmological model based on unparticles that naturally produces dark energy and a deSitter phase, avoiding common theoretical issues.

Findings

Unparticles behave like radiation at high energies, reducing Hubble tension.

Unparticles act as a cosmological constant at low energies, mimicking ΛCDM.

The model is technically natural and free from the coincidence and initial conditions problems.

Abstract

A limiting temperature of a species can cause the Universe to asymptote to it yielding a deSitter (dS) phase due to macroscopic emergent behavior. The limiting temperature is generic for theories slightly shifted from their conformal point. We demonstrate such behavior in the example of unparticles/Banks-Zaks theory. The unparticles behave like radiation at high energies reducing the Hubble tension, and a cosmological constant (CC) at low energies yielding a model that follows closely {\Lambda}CDM model but due to collective phenomenon. It is technically natural and avoids the no-dS conjecture. The model is free of the coincidence and initial conditions problems, of scalar fields and of modified gravity.