Gravothermal Collapse of Self-Interacting Dark Matter Halos and the Origin of Massive Black Holes

Black hole formation is an inevitable consequence of relativistic core collapse following the gravothermal catastrophe in self-interacting dark matter (SIDM) halos. Very massive SIDM halos form supermassive black holes (SMBHs) $\gtrsim {10}^6{M}_{\odot }$ directly. Smaller halos believed to form by redshift $z=5\mathrm{}$ produce seed black holes of $({10}^2–{10}^3)M_{\odot }$ which can merge and/or accrete to reach the observational SMBH range. This scenario for SMBH formation requires no baryons, no prior star formation, and no other black hole seed mechanism.