Cosmic coincidences of primordial-black-hole dark matter

Speaker :  Dr. Yi-Peng Wu (AS, IoP)

Abstract :
If primordial black holes (PBHs) contribute more than 10 percent of the dark matter (DM) density, their energy density today is of the same order as that of the baryons. Such a cosmic coincidence might hint at a mutual origin for the formation scenario of PBHs and the baryon asymmetry of the Universe. In this talk, I will introduce how baryogenesis can be triggered by the so-called ultra-slow-roll inflation that produces large curvature perturbations for PBH formation in single-field inflationary models. Within the inferred mass range for PBHs as important DM components, the "cosmic coincidence" requirement restricts the scaling frequencies of the stochastic gravitational wave background induced by ultra-slow-roll inflation, which can be tested by future experiments such as LISA, Einstein Telescope or DECIGO.