Non-linear preheating after inflation and gravitational wave production by Mar Bastero-Gill - Universidad de Granada (Espagne)

Tuesday 23 Jun 2009, 14:00 → 15:00 Europe/Paris

amphi (LPSC)

We discuss the evolution of the coupled system field-gravity during "preheating" after inflation, obtained by integrating the full set of Einstein equations with matter sources provided by the inflaton field and fields coupled to it. Parametric amplification of field fluctuations has been extensively studied over the last years, and more recently it has been studied the possible production of primordial gravitational waves during preheating, sourced by the (parametrically amplified) field fluctuations. These results indicate that in certain class of models a background of gravity waves is generated within the possible reach of future gravity wave experiments. We have studied the evolution of the full set of equations in a generic hybrid model, also taking into account the effect of the expansion rate during preheating, neglected in previous studies. Preliminary results obtained when including during preheating all kind of metric perturbations show a tendency to increase the value of the amplitude of the primordial gravitational waves, compared to previous results taking into account only the system field-tensor perturbations.