Vortragsdetails

Mittwoch, 27. Januar 2010 - 15:15

Elisabetta Majerotto:

"Perturbations and observational constraints on an interacting dark energy model"

Zusammenfassung. I will present an interacting dark energy model, where the interaction is proportional to the dark matter density. 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. As supernovae Ia or baryon acoustic oscillation data require the recent-time equation of state parameter to be more negative than the early-time equation of state, we consider a time-varying equation of state in our model. We apply the derived initial conditions and 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.