Inflationary theory and pulsar timing investigations of primordial black
  holes and gravitational waves
  The gravitational waves measured at LIGO are presumed here to come from
merging primordial black holes. We ask how these primordial black holes could
arise through inflationary models while not conflicting with current
experiments. Among the approaches that work, we investigate the opportunity for
corroboration through experimental probes of gravitational waves at pulsar
timing arrays. We provide examples of theories that are already ruled out,
theories that will soon be probed, and theories that will not be tested in the
foreseeable future. The models that are most strongly constrained are those
with a relatively broad primordial power spectrum.
