The Cosmogony of Super-Massive Black Holes
  We report results of a project investigating the growth of super-massive black holes (BHs) by disk accretion. We find that the BH mass growth is quick enough to account for the inferred masses in the highest-redshift quasars, and the growth time is an inverse function of the final BH mass as seems to be required by recent X-ray surveys. 
Wolfgang J. Duschl (1,2) and Peter A. Strittmatter (2) ((1) Institut   fuer Theoretische Astrophysik, Heidelberg, Germany, (...