The Andante Regime of Scalar Field Dynamics
  The andante regime of scalar field dynamics in the chaotic inflationary Universe is defined as the epoch when the field is rolling moderately slowly down its interaction potential, but at such a rate that first-order corrections to the slow-roll approximation become important. These conditions should apply towards the end of inflation as the field approaches the global minimum of the potential. Solutions to the Einstein-scalar field equations for the class of power law potentials $V(\phi) \propto \phi^{2n}$ are found in this regime in terms of the inverse error function. 
James E. Lidsey and I. Waga