Adiabatic initial conditions for perturbations in interacting dark energy models

作者：Majerotto Elisabetta^*; Vaeliviita Jussi; Maartens Roy

来源：Monthly Notices of the Royal Astronomical Society, 2010, 402(4): 2344-2354.

DOI：10.1111/j.1365-2966.2009.16140.x

• cosmic microwave background
• cosmological parameters
• cosmology: theory
• dark matter

We present a new systematic analysis of the early radiation era solution in an interacting dark energy model to find the adiabatic initial conditions for the Boltzmann integration. In a model where the interaction is proportional to the dark matter density, adiabatic initial conditions and viable cosmologies are possible if the early-time dark energy equation of state parameter is w(e) > -4/5. We find that when adiabaticity between cold dark matter, baryons, neutrinos and photons is demanded, the dark energy component satisfies automatically the adiabaticity condition. As Type Ia supernovae or baryon acoustic oscillation data require the recent-time equation of state parameter to be more negative, we consider a time-varying equation of state in our model. In a companion paper, we apply the initial conditions derived here and perform a full Monte Carlo Markov Chain likelihood analysis of this model.

• 出版日期2010-3