The Clustering Dynamics of Primordial Black Holes in N-Body Simulations

We explore the possibility that Dark Matter (DM) may be explained by a non-uniform background of approximately stellar-mass clusters Primordial Black Holes (PBHs), simulating evolution them from recombination to present with over 5000 realisations using Newtonian $ N $-body code. compute cluster rate evaporation, and extract binary merged sub-populations along their parent merger tree histories, lifetimes formation rates; dynamical orbital parameter profiles, degree mass segregation friction, power spectrum close encounters. Overall, we find PBHs can constitute viable DM candidate, clustering presents rich phenomenology throughout history Universe. show systems about 9.5\% all at present, ratios \bar{q}_{\rm B} = 0.154 $, total masses \bar{m}_{\rm T,\,B} 303\,M_\odot$. Merged are rare, 0.0023\% B}= 0.965 chirp T,\,B}= 1670\,M_\odot$ \bar{m}_{c,{\rm M}} 642\,M_\odot respectively. puffing up evaporation leads bubbles these order 1 kpc containing times 36\% objects mass, hundred pc sized cores. also PBH sub-haloes distributed in wider haloes hundreds kpc, 63\% coinciding sizes galactic halos. last high rates encounters massive ($ M \sim 1000\,M_\odot$), \Gamma^{\mathrm{S}} (1.2^{+5.9}_{-0.9}) \times 10^{7} \mathrm{yr^{-1} Gpc^{-3}}$ mergers $\Gamma^{\mathrm{M}} 1337 \pm 41 Gpc^{-3}} $.