Abstract:
I discuss how the bound on the amplitude of isocurvature perturbations
imply that gravitationally produced superheavy dark matter must have
masses larger than few times the Hubble expansion rate at the end of
inflation. This induces a fairly robust lower bound on the reheating
temperature for superheavy dark matter to be about 10^{7} GeV.  Hence, if
the superheavy dark matter scenario is embedded in supergravity models
with gravity mediated SUSY breaking, the gravitino bound will squeeze this
scenario.