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The purely gravitational dark matter (PGDM) which interacts with the standardmodel particles only by gravitational interaction has recently been discussed.Due to its feeble interaction, PGDM may be produced mainly by the gravitationalparticle creation, which plays an important role in the reheating afterkinetically driven inflation and some potential-driven inflation withoutsubsequent inflaton oscillating phase. Therefore, we consider the possibilityof the gravitational reheating model which can also explain the present PGDMdensity at the same time. We consider a model where two massive scalar fieldsare incorporated into the standard model besides the inflation sector. We showthat the gravitational particle creation prevails over the thermal creation ---the freeze-in process --- and it can actually explain the reheating and thepresent abundance of dark matter if one of the scalar particles is as heavy asthe Hubble parameter during inflation $\sim10^{13}$ GeV and finally decays intoradiation via sufficiently weak coupling, and the other is a stable PGDM withits mass of the order of $10^3$ GeV.

Gravitational particle creation for dark matter and reheating