Abstract:
My presentation will discuss the role of Primordial Black Holes (PBHs) as one of DM components throughout cosmic history. I will specifically focus on PBH candidates in the solar mass range of approximately 10-100 $M_{\odot}$ and massive PBHs of $10^6 M_{\odot}$ as possible seeds for supermassive black holes (SMBHs).
Our research utilizes N-body simulations with the GIZMO code and semi-analytical models to investigate PBHs' impact. We find that stellar-mass PBHs, ranging from 10-100 $M_{\odot}$ and constituting a fraction of $10^{-4}$ to $0.1$ of DM, subtly influence the formation of the universe’s first stars by maintaining the standard model of star formation, while their accretion feedback shifts star formation to more massive halos. Additionally, PBHs significantly contribute to the cosmic radiation background during reionization, but do not violate existing constraints on the timing of reionization. On the other hand, more massive PBHs with $10^6 M_{\odot}$, could seed massive halos and disrupt hierarchical structure formation by engulfing newly formed halos. In contrast to the effects from stellar-mass PBHs, our recent studies reveal that the narrative of early star formation is complicated by initial perturbations and accretion feedback from these massive PBHs at very high redshifts.
