Multifield Dirac-Born-Infeld inflation and non-Gaussianities

We analyze the trajectories for multifield Dirac-Born-Infeld inflation, which can arise in brane inflation models, and show that the trajectories are the same as in typical slow roll inflation. We calculate the power spectrum and find that the higher derivative terms of the Dirac-Born-Infeld action lead to a suppression of the contribution from the isocurvature perturbations. We also calculate the bispectrum generated by the isocurvature perturbation, and find that it leads to distinctive features.