Preheating and the dark sector of the universe

Regarding long-life particle produced during preheating after inflation as dark matter, we find that its backreaction on the field φ can lock φ in a false vacuum up to today under certain conditions. This false vacuum can drive the accelerated expansion of universe at late time and play the role of dark energy. When the number density of dark matter particle is diluted to some value, the field φ will become tachyonic and roll to its true minimum rapidly, and the acceleration of universe ceases. We discuss the constraints on the parameters of model from the observations