Double inflation as a single origin of primordial black holes for all dark matter and LIGO observations

Primordial Black Hole (PBH) is one of the leading non-particle candidates for dark matter (DM). Although several observations severely constrain the amount of PBHs, it is recently pointed out that there is an uncertainty on the microlensing constraints below ∝10^-10M_sun which was ignored originally but may weaken the constraints significantly. In this paper, facing this uncertainty, we investigate the possibility that PBHs can make up all DM in a broad mass spectrum. Moreover, we propose a concrete inflation model which can simultaneously produce PBHs for all DM in a broad mass spectrum around O(10^-13)M_sun and PBHs for LIGO events in a sharp mass spectrum at O(10)M_sun.