Collisional Dark Matter and the Origin of Massive Black Holes

TL;DR

If the cosmological dark matter is primarily in the form of an elementary particle which has mass m(p) and cross section for self-interaction sigma, then seed black holes will grow in a Hubble time t(H) due to accretion of the dark matter to a mass, which produces massive black holes in the (10(6)-10(9) range observed.

Abstract

If the cosmological dark matter is primarily in the form of an elementary particle which has cross section and mass for self-interaction having a ratio similar to that of ordinary nuclear matter, then seed black holes (formed in stellar collapse) will grow in a Hubble time, due to accretion of the dark matter, to a mass range 10^6 - 10^9 solar masses. Furthermore, the dependence of the final black hole mass on the galaxy velocity dispersion will be approximately as observed and the growth rate will show a time dependence consistent with observations. Other astrophysical consequences of collisional dark matter and tests of the idea are noted.