Abstract

We use semi-analytical models to study the effects of primordial black holes (PBHs) accretion on the cosmic radiation background before the epoch of reionization (z≳6). Our previous work found that PBHs with stellar mass (∼1−100M⊙) do not significantly change the standard picture of Pop III star formation. In this work, we will assume a similar mass range for PBHs and consider both cases of PBHs floating in the intergalactic medium (IGM) and inside halos, where star formation could occur. To better estimate the background radiation level, we combined the feedback radiation in halos from BHs of all sources, including PBHs, astrophysical black holes (ABHs) from remnants of more massive stars, and supermassive black holes (SMBHs). We will also study the change of PBHs to the structure formation and use this change to model the halo mass function correctly. We hope the study of imprints from PBHs will help us distinguish them from the rest of the BHs.