Does Inflationary Particle Production suggest Omega_m < 1?

We study a class of FRW spacetimes with a nonminimally coupled light massive scalar field. Values of the coupling parameter xi<0 enhance long range power in the vacuum expectation value of the energy-momentum tensor and fundamentally alter the nature of inflationary particle production: the energy density of created particles behaves like an effective cosmological constant, leading generically to Omega_m < 1 in clustered matter and providing a possible resolution of the ``Omega problem'' for low density cosmological models.