Theory HEP Seminar

Collapse of small-scale density perturbations during preheating and production of gravitational waves

Jerome Martin

IAP

After cosmic inflation and before the transition to radiation domination, the cosmic energy density may have been dominated during an extended period by an oscillating massive scalar condensate, the so-called pre/re heating epoch. We show that, during this period, a wide range of sub-Hubble scale perturbations are subject to a preheating instability, leading to the growth of density perturbations ultimately collapsing to form non-linear structures. These early structures may lead to the emission of gravitational waves that we calculate.We show that the signal is potentially detectable.