Second order invariants and holography

TL;DR

This paper explores the use of second order Ricci invariants to define a holographic dark energy model that addresses causality issues and fits observational data well, offering solutions to fine-tuning and coincidence problems.

Contribution

It introduces a novel approach using second order Ricci invariants for holographic dark energy, avoiding causality issues linked to event horizons.

Findings

Models fit observational data well including SNeIa, BAO, and CMB.

The approach overcomes fine-tuning and coincidence problems.

Statistical tests favor the proposed models over alternatives.

Abstract

Motivated by recent works on the role of the Holographic principle in cosmology, we relate a class of second order Ricci invariants to the IR cutoff characterizing the holographic Dark Energy density. The choice of second order invariants provides an invariant way to account the problem of causality for the correct cosmological cutoff, since the presence of event horizons is not an \emph{a priori} assumption. We find that these models work fairly well, by fitting the observational data, through a combined cosmological test with the use of SNeIa, BAO and CMB. This class of models is also able to overcome the fine-tuning and coincidence problems. Finally, to make a comparison with other recent models, we adopt the statistical tests AIC and BIC.