I discuss the cosmology of Primordial Black Holes (PBHs) produced by density perturbations and consider the scenario that PBHs and the remnants of PBHs constitute a significant fraction of the dark matter in the galaxies.
I introduce inflationary models that generate PBHs and, additionally, give rise to fast and slow reheating and kination post-inflationary domination eras.
I also present the spectral shapes of gravitational waves (GWs) induced to second order by large scalar perturbations and demonstrate the ability of the GWs to reveal the spectrum of the primordial curvature perturbations at scales much smaller than those directly accessible in the CMB.