Stochastic Gravitational-Wave Background due to Primordial Binary Black
  Hole Mergers
  Recent Advanced LIGO detections of binary black hole mergers have prompted
multiple studies investigating the possibility that the heavy GW150914 binary
system was of primordial origin, and hence could be evidence for dark matter in
the form of black holes. We compute the stochastic background arising from the
incoherent superposition of such primordial binary black hole systems in the
universe and compare it to the similar background spectrum due to binary black
hole systems of stellar origin. We investigate the possibility of detecting
this background with future gravitational wave detectors, and discuss the
possibility of using the stochastic gravitational-wave background measurement
to constrain the dark matter component in the form of black holes.
