The Growth of the Stellar Seeds of Supermassive Black Holes
  One of the most promising explanations for the origin of the billion solar
mass black holes (BHs) inferred to power quasars at redshifts z > 6 is that
supermassive stars (SMSs) with masses > 10,000 solar masses collapse to form
the seed BHs from which they grow. Here we review recent theoretical advances
which provide support for this scenario. Firstly, given sufficiently high
accretion rates of gas into the cores of primordial protogalaxies, it appears
that neither the high energy radiation emitted from the stellar surface nor the
limited lifetime of SMSs can prevent their growth to masses of up to > 100,000
solar masses. Secondly, recent cosmological simulations suggest that the high
fluxes of molecule-dissociating radiation which may be required in order to
achieve such high accretion rates may be more common in the early universe than
previously thought. We conclude that the majority of supermassive BHs may
originate from SMSs at high redshifts.
