Inflationary attractor in the braneworld scenario

We demonstrate the attractor behavior of inflation driven by a scalar or tachyon field in the context of the recently proposed four-dimensional effective gravity induced on the world-volume of a three-brane in five-dimensional Einstein gravity, and we obtain a set of exact inflationary solutions. The phase portraits indicate that an initial kinetic term decays rapidly and does not prevent the onset of inflation. The trajectories more rapidly reach the slow rolling curve in the braneworld scenario than in the standard cosmology.