2021/09/30 by Eloy de Jong, Josu C. Aurrekoetxea, Eugene A. Lim
Physics and Astronomy · #Accretion (finance) #Astrophysics #Black hole (networking) #Classical mechanics #Cosmology and Gravitation Theories #Dark matter #Galaxies: Formation, Evolution, Phenomena #Galaxy #General relativity #Gravitational collapse #Numerical relativity #Perturbation (astronomy) #Physics #Primordial black hole #Pulsars and Gravitational Waves Research #Quantum mechanics #Spin-flip #Structure formation #Theory of relativity #astro-ph.CO #gr-qc
paper · pdf · doi:10.1088/1475-7516/2022/03/029
published as JCAP03(2022)029 · 12 pages, 8 figures. 2 YouTube videos here: https://youtube.com/playlist?list=PLSkfizpQDrcZuKZPQydJA9l_pxxWpqIMz
openalex publication_date 2022/03/01 · arxiv created 2022/03/24 · arxiv updated 2022/03/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We study the formation of black holes from subhorizon and superhorizon perturbations in a matter dominated universe with 3+1D numerical relativity simulations. We find that there are two primary mechanisms of formation depending on the initial perturbation's mass and geometry -- via direct collapse of the initial overdensity and via post-collapse accretion of the ambient dark matter. In particular, for the latter case, the initial perturbation does not have to satisfy the hoop conjecture for a black hole to form. In both cases, the duration of the formation the process is around a Hubble time, and the initial mass of the black hole is MBH ∼ 10-2 H-1 MPl2. Post formation, we find that the PBH undergoes rapid mass growth beyond the self-similar limit MBH∝ H-1, at least initially. We argue that this implies that most of the final mass of the PBH is accreted from its ambient surroundings post formation.