Black Hole Formation in the First Stellar Clusters
  The early Universe was composed almost entirely of hydrogen and helium, with
only trace amounts of heavy elements. It was only after the first generation of
star formation that the Universe became sufficiently polluted to produce a
second generation (Population II) of stars which are similar to those in our
local Universe. Evidence of massive star cluster formation is nearly ubiquitous
among the observed galaxy population and if this mode of star formation
occurred at early enough epochs, the higher densities in the early Universe may
have caused many of the stars in the cluster to strongly interact. In this
scenario, it may be possible to form a very massive star by repeated stellar
collisions that may directly collapse into a black hole and form a supermassive
black hole seed. In this chapter, we will explore this scenario in detail to
understand the dynamics which allow for this process to ensue and measure the
probability for this type of seed to represent the supermassive black hole
population observed at z > 6.
