Evolution of density perturbations in decaying vacuum cosmology

Understand

We study cosmological perturbations in the context of an interacting dark energy model, in which the cosmological term decays linearly with the Hubble parameter, with concomitant matter production.

• A previous joint analysis of the redshift-distance relation for type Ia supernovas, baryonic acoustic oscillations, and the position of the first peak in the anisotropy spectrum of the cosmic microwave background has led to acceptable values for the cosmological parameters.
• Here we present our analysis of small perturbations, under the assumption that the cosmological term, and therefore the matter production, are strictly homogeneous.
• Such a homogeneous production tends to dilute the matter contrast, leading to a late-time suppression in the power spectrum.