Inflation on a Warped Dvali-Gabadadze-Porrati Brane
  We discuss an inflation model, in which the inflation is driven by a single scalar field with exponential potential on a warped DGP brane. In contrast to the power law inflation in standard model, we find that the inflationary phase can exit spontaneously without any mechanism. The running of the index of scalar perturbation spectrum can take an enough large value to match the observation data, while other parameters are in a reasonable region. 
Rong-Gen Cai and Hongsheng Zhang