Gravitational waves from resonant amplification of curvature perturbations during inflation

Understand

Parametric resonance in a single-field inflationary model with a periodic structure on the potential gives rise to curvature perturbations with large amplitudes on small scales, which could result in observable primordial black holes (PBHs) and concomitant gravitational waves (GWs) induced by curvature perturbations in the radiation-dominated era.

• In such a model, GWs associated with the PBH formation were investigated in Ref.
• [1].
• In this paper, we consider a stochastic GW background sourced by inflaton perturbations resonantly amplified during inflation.