Do WMAP5 data favor neutrino mass and a coupling between Cold Dark Matter and Dark Energy?

Abstract

We fit WMAP5 and related data by allowing for a CDM--DE coupling and non--zero neutrino masses, simultaneously. We find a significant correlation between these parameters, so that simultaneous higher coupling and \nu--masses are allowed. Furthermore, models with a significant coupling and \nu--mass are statistically favoured in respect to a cosmology with no coupling and negligible neutrino mass (our best fits are: C ~ 1/2m_p, m_\nu ~ 0.12eV per flavor). We use a standard Monte Carlo Markov Chain approach, by assuming DE to be a scalar field self--interacting through Ratra--Peebles or SUGRA potentials.