Primordial black holes and induced gravitational waves from inflation in the Horndeski theory of gravity

Understand

We investigate the production of primordial black holes (PBHs) and scalar-induced gravitational waves (GWs) for cosmological models in the Horndeski theory of gravity.

• The cosmological models of our interest incorporate the derivative self-interaction of the scalar field and the kinetic coupling between the scalar field and gravity.
• We show that the scalar power spectrum of the primordial fluctuations can be enhanced on small scales due to these additional interactions.
• Thus, the formation of PBHs and the production of induced GWs are feasible for our model.