New constraints on interacting dark energy from cosmic chronometers

TL;DR

This study constrains models of interacting dark energy using cosmic chronometers, supernovae, BAO, and CMB data, finding a mild interaction and a dark energy equation-of-state parameter less than -1.

Contribution

It provides new observational constraints on interacting dark energy models by combining multiple cosmological probes and recent precise measurements.

Findings

Dark energy interacts mildly with dark matter.

Dark energy equation-of-state parameter w < -1 at 3σ confidence.

Interaction models are consistent with current data.

Abstract

We use the latest compilation of observational Hubble parameter measurements estimated with the differential evolution of cosmic chronometers, in combination with the local value of the Hubble constant recently measured with 2.4% precision, to constrain the cosmological scenario where dark energy interacts directly with the dark matter sector. To diminish the degeneracy between the parameters we additionally consider standard probes, such as Supernovae Type Ia from joint light curves (JLA) sample, Baryon Acoustic Oscillation distance measurements (BAO), and cosmic microwave background data from Planck 2015 estimations. Our analysis shows that the direct interaction between dark energy and dark matter is mildly flavored, while the dark energy equation-of-state parameter is w < - 1 at 3$\sigma$ confidence level.