Do WMAP data favor neutrino mass and a coupling between Cold Dark Matter and Dark Energy?

TL;DR

This study investigates whether WMAP data support models with neutrino masses and a coupling between Cold Dark Matter and Dark Energy, finding such models are as plausible or favored compared to standard cosmology.

Contribution

It introduces a combined analysis of CDM-DE coupling and neutrino masses within scalar field dark energy models using MCMC methods, expanding prior cosmological model assessments.

Findings

CDM-DE coupling and neutrino masses are as likely as standard models.

Models with these features can be statistically favored by WMAP data.

Neutrino masses around 0.1 eV per species are compatible with observations.

Abstract

Within the frame of cosmologies where Dark Energy (DE) is a self--interacting scalar field, we allow for a CDM--DE coupling and non--zero neutrino masses, simultaneously. In their 0--0 version, i.e. in the absence of coupling and neutrino mass, these cosmologies provide an excellent fit to WMAP, SNIa and deep galaxy sample spectra, at least as good as \LambdaCDM. When the new degrees of freedom are open, we find that CDM--DE coupling and significant neutrino masses (~0.1eV per \nu species) are at least as likely as the 0--0 option and, in some cases, even statistically favoured. Results are obtained by using a Monte Carlo Markov Chain approach.