摘要: It is well known that a primordial black hole (PBH) can be generated in the
inflation process of the early universe, especially when the inflation field
has a number of non-trivial features that could break the slow-roll condition.
In this study, we investigate a toy model of inflation with bumpy potential,
which has one or several bumps. We determined that the potential with
multi-bump can generate power spectra with multi-peaks in small-scale region,
which can in turn predict the generation of primordial black holes in various
mass ranges. We also consider the two possibilities of PBH formation by
spherical and elliptical collapses. Finally, we discuss the scalar-induced
gravitational waves(SIGWs)generated by linear scalar perturbations at second
order.