******** CTCD/NTHU HEP Seminar ********

Speaker : Prof. Feng-Li Lin (NTNU)

Title ：Supermassive Black Hole Formations via Bondi Accretion of Self-Interacting Dark Matter

Time ：12:30-13:30, Thursday, 2026/5/14

Place ：R521, 5F, General Building II, Nat'l Tsing Hua Univ.

Host ： Prof. Kingman Cheung (NTHU) & Prof. Norihiro Iizuka (NTHU)

Abstract:
In this talk, I will discuss a recent ApJL article of mine with Chian-Shu Chen (Tamkang U) on a super-Eddington accretion mechanism aided by the Bondi accretion of a minimal model of self-interacting dark matter (SIDM). We demonstrate that in a critical regime with a near-relativistic sound speed, Bondi accretion yields an accretion rate that depends only on the mass m of SIDM; thus, it is universal across ambient environments. This critical accretion mechanism for m ≳ 10^{−2} eV can grow seeds as small as 10 M⊙ primordial black holes (PBHs) in the early Universe into 10^9–10^{10} M⊙ SMBHs by z ∼ 7 without fine-tuned environments. Therefore, given a mass distribution of PBHs and a value of m, the mass function of primary black holes at late time can be fully determined with masses ranging from stellar to SMBHs. This connects the microscopic physics of dark matter to the recent astrophysical observations of supermassive black holes at high redshifts by JWST.