  We consider a non-minimally coupled inflaton, in a higher order curvature
background, leading to a potential which evolves with the curvature scalar of
the Universe, and which describes two regimes. The first one is a de Sitter
phase, where the potential is static, and an exact exponential solution is
found for the inflaton. The second regime, triggered by the inflaton reaching a
threshold, leads to a power-law expansion, during which the potential becomes
flat, quickly enough for the inflaton never to reach the minimum of the initial
symmetry breaking potential. This scenario is an alternative to the inflaton
oscillating about a minimum of the potential, and where preheating is a
consequence of the flattening of the potential during the power-law expanding
phase.
