Description
A number of inflationary scenarios seeding PBH from adiabatic perturbations also lead to the production of localized eternally inflating relics, which in turn also lead to the formation of PBH once the ambient universe thermalizes. Here, we compare the relative contribution from both channels, focusing on the case of a transient ultra-slow roll (USR) phase followed by a sharp transition to slow roll. Special attention is given to the distribution of initial conditions for high peaks, including the relevant mean profiles and shape dispersion around them. The profiles are numerically evolved to determine the thresholds for both channels. Our analysis essentially validates the logarithmic template for non-Gaussianity, whose divergence signals the onset of eternal inflation. Observational consequences are briefly discussed.