Knowledge Bank

Primordial black holes (PBHs) are theoretical compact objects that may have formed in the early universe and could constitute a significant fraction of dark matter. A method to constrain the allowed mass range of PBHs is through the stellar capture process, in which a PBH passes through a star, experiences gravitational drag via dynamical friction, and potentially becomes bound. However, at lower PBH masses, radiation from accretion heating can counteract this drag and prevent capture. This thesis models the accretion and radiation around PBHs in a solar-type star using Bondi flow and bremsstrahlung emission with relativistic corrections. A Monte Carlo simulation is used to trace photon propagation and energy deposition, allowing for a Fourier-space calculation of the radiative drag. Results show that above a critical luminosity threshold, radiative heating dominates and produces a net acceleration, suppressing capture. This implies that the population of PBHs may be larger than previously expected, refining their viability as dark matter candidates.