Primordial Fluctuations and Non-Gaussianities in Multifield Dirac-Born-Infeld Inflation
Primordial Fluctuations and Non-Gaussianities in Multifield Dirac-Born-Infeld Inflation
We study Dirac-Born-Infeld inflation models with multiple scalar fields. We show that the adiabatic and entropy modes propagate with a common effective sound speed and are thus amplified at the sound horizon crossing. In the small sound speed limit, we find that the amplitude of the entropy modes is much …