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 $\sim {10}^{-10}{M}_{\odot }$ 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 $\mathcal{O}({10}^{-13})M_{\odot }$ and PBHs for LIGO events in a sharp mass spectrum at $\mathcal{O}(10)M_{\odot }$.