Non-gaussianity from the bispectrum in general multiple field inflation

Understand

We study the non-gaussianity from the bispectrum in multi-field inflation models with a general kinetic term.

• The models include the multi-field K-inflation and the multi-field Dirac-Born-Infeld (DBI) inflation as special cases.
• We find that, in general, the sound speeds for the adiabatic and entropy perturbations are different and they can be smaller than 1.
• Then the non-gaussianity can be enhanced.