The early evolution of massive black holes
  Massive black holes are nowadays believed to reside in most local galaxies.
Studies have also established a number of relations between the MBH mass and
properties of the host galaxy such as bulge mass and velocity dispersion. These
results suggest that central MBHs, while much less massive than the host
(~0.1%), are linked to the evolution of galactic structure. When did it all
start? In hierarchical cosmologies, a single big galaxy today can be traced
back to the stage when it was split up in hundreds of smaller components. Did
MBH seeds form with the same efficiency in small proto-galaxies, or did their
formation had to await the buildup of substantial galaxies with deeper
potential wells? I briefly review here some of the physical processes that are
conducive to the evolution of the massive black hole population. I will discuss
black hole formation processes for `seed' black holes that are likely to place
at early cosmic epochs, and possible observational tests of these scenarios.
