Coupling between cold dark matter and dark energy from neutrino mass experiments

TL;DR

This study explores the interaction between dark energy and dark matter in cosmology, revealing a strong link with neutrino mass measurements, and suggests that neutrino experiments could confirm dark sector coupling.

Contribution

It demonstrates a significant correlation between dark sector coupling and neutrino mass, showing that neutrino experiments can provide evidence for dark energy-dark matter interaction.

Findings

Strong correlation between coupling strength and neutrino mass.

Detection of neutrino mass implies a significant dark sector coupling.

Coupling model improves over previous dark energy models with w < -1.

Abstract

We consider cosmological models with dynamical dark energy (dDE) coupled to cold dark matter (CDM), while simultaneously allowing neutrinos to be massive. Using a MCMC approach, we compare these models with a wide range of cosmological data sets. We find a strong correlation between this coupling strength and the neutrino mass. This correlation persists when BAO data are included in the analysis. We add then priors on $\nu$ mass from particle experiments. The claimed detection of $\nu$ mass from the Heidelberg-Moscow neutrinoless double--$\beta$ decay experiment would imply a 7--$8 \sigma$ detection of CDM-DE coupling. Similarly, the detection of $\nu$ mass from coming KATRIN tritium $\beta$ decay experiment will imply a safe detection of a coupling in the dark sector. Previous attempts to accommodate cosmic phenomenology with such possible $\nu$ mass data made recourse to a $w < -1$ eoS. We compare such an option with the coupling option and find that the latter allows a drastic improvement.