Abstract

We discuss formation of dark matter (DM) mini-halos around primordial black holes (PBHs) and its implication on DM direct detection experiments, including axion searches. Motivated by LIGO observations, we consider f(DM) similar to 0.01as the fraction of DM in PBHs with masses 10M(circle dot) - 70M(circle dot). In this case, we expect the presence of dressed PBHs after Milky Way halo formation with mini-halo masses peaked around M-halo similar to(50 - 55)M-PBH. We analyze the effect of tidal forces acting on dressed PBHs within the Milky Way galaxy. In the solar neighborhood, the mini-halos are resistant against tidal disruption from the mean-field potential of the galaxy and encounters with stars, but they undergo a small level of disruption caused by disk shocking. The presence of mini-halos around LIGO-motivated PBHs today could reduce by half the local dark matter background. High-resolution simulations are encouraged. If the proposed scenario is realized, chances of direct detection of DM would decrease. (C) 2020 The Authors. Published by Elsevier B.V.