| Abstract: |
Quantum evaporation of a black hole is conventionally studied semiclassically by assuming self-similarity of the black hole throughout the evaporation process. However, its validity was recently questioned, and the lifetime of a black hole is conjectured to be much extended by the memory burden effect. It gives rise to the possibility that the primordial black holes (PBHs) lighter than 10^10 grams are the dark matter in the Universe. To probe such PBH dark matter, we study gravitational waves (GWs) induced by primordial curvature perturbations that produced the PBHs. We find that the PBH dark matter whose initial mass is greater than about 10^7 grams is associated with the high-frequency induced GWs that can be tested by future observations such as Cosmic Explorer. In principle, the scenario can be confirmed by detecting another GW signal from the mergers of PBHs, which leads to extremely high- frequency GWs. On the other hand, the induced GW signals stronger than expected would contradict the dark matter abundance and exclude the memory burden effect. |
