Searching for Dark Matter Constituents with Many Solar Masses
  Searches for dark matter (DM) constituents are presently mainly focused on
axions and WIMPs despite the fact that far higher mass constituents are viable.
We discuss and dispute whether axions exist and those arguments for WIMPs which
arise from electroweak supersymmetry. We focus on the highest possible masses
and argue that, since if they constitute all DM they cannot be baryonic, they
must uniquely be primordial black holes. Observational constraints require them
to be of intermediate masses mostly between a hundred and a hundred thousand
solar masses. Known search strategies include wide binaries, CMB distortion
and, most promisingly, extended microlensing experiments.
