Properties of holographic dark energy at the Hubble length

TL;DR

This paper explores holographic dark energy models with the Hubble radius as the cutoff, showing how interacting models can be reformulated as non-interacting with evolving parameters, and constrains these models using observational data.

Contribution

It demonstrates that all interacting holographic dark energy models can be equivalently described as non-interacting models with a slowly evolving holographic parameter, providing a new perspective.

Findings

Models can be distinguished at the perturbative level.

Constraints on model parameters from observational data.

Reformulation simplifies analysis of interacting models.

Abstract

We consider holographic cosmological models of dark energy in which the infrared cutoff is set by the Hubble's radius. We show that any interacting dark energy model, regardless of its detailed form, can be recast as a non interacting model in which the holographic parameter $c^{2}$ evolves slowly with time. Two specific cases are analyzed. We constrain the parameters of both models with observational data, and show that they can be told apart at the perturbative level.