  We discuss two possible scenarios, namely the curvaton mechanism and the dark
matter density modulation, where non-Gaussianity signals of superheavy dark
matter produced by gravity can be enhanced and observed. In both scenarios,
superheavy dark matter couples to an additional light field as a mediator. In
the case of derivative coupling, the resulting non-Gaussianities induced by the
light field can be large, which can provide inflationary evidences for these
superheavy dark matter scenarios.
