Gravitational wave spectra from oscillon formation after inflation

Understand

We systematically investigate the preheating behavior of single field inflation with an oscillon-supporting potential.

• We compute the properties of the emitted gravitational waves (GWs) and the number density and characteristics of the produced oscillons.
• By performing numerical simulations for a variety of potential types, we divide the analyzed potentials in two families, each of them containing potentials with varying large- or small-field dependence.
• We find that the shape and amplitude of the emitted GW spectrum have a universal feature, with the peak around the physical wavenumber $k/a \sim m$ at the inflaton oscillation period, irrespective of the exact potential shape.