Non-Gaussianities in DBI inflation with angular motion

Understand

We study DBI spinflation models with angular potentials that are derived in string theory.

• We analyse the background dynamics with different parameter sets and study the impact of changing each parameter on inflationary dynamics.
• It is known that the conversion of the entropy perturbation into the curvature perturbation gives multi-field DBI inflation models a possibility of satisfying the observational constraints by relaxing the stringent microphysical constraint that disfavours single field DBI inflation models.
• we show that our model is excluded by the Planck satellite observations even with the conversion mechanism regardless of the parameter set.