$H(z)$ diagnostics on the nature of dark energy

TL;DR

This paper introduces criteria based on the Hubble parameter's history to determine if dark energy interacts with matter and to distinguish its nature as phantom or quintessence, aiding understanding of cosmic acceleration.

Contribution

It proposes novel diagnostics using H(z) data to identify interactions between dark energy and matter and to classify dark energy's nature.

Findings

Criteria can differentiate interacting and non-interacting dark energy models.

Methods can distinguish phantom from quintessence dark energy.

Applicable to current and future observational data.

Abstract

The two dominant components of the cosmic budget today, pressureles matter and dark energy, may or may not be interacting with each other. Currently, both possibilities appear compatible with observational data. We propose several criteria based on the history of the Hubble factor that can help discern whether they are interacting and whether dark energy is phantom or quintessence in nature.