Cosmological perturbations and observational constraints on an interacting dark energy model

by Dr Elisabetta Majerotto (Osservaorio Astronomico di Brera)

Friday 4 Jun 2010, 10:30 → 11:30 Europe/Zurich

Auditoire 234 (Université de Genève)

I will present an interacting dark energy model, where the interaction is proportional to the dark matter density and the dark energy equation of state is time-varying. I will show the conditions to be imposed on the early-time dark energy equation of state parameter in order to give adiabatic initial conditions and viable cosmologies. We perform a full Monte Carlo Markov Chain likelihood analysis of this model. We use observations of cosmic microwave background anisotropies, supernova luminosities and the baryon acoustic oscillation signal in the galaxy distribution to constrain the cosmological parameters and find that the combination of the three data sets confines the interaction constant to be less than 23% of the expansion rate of the Universe.