Curvaton with Nonminimal Derivative Coupling to Gravity II: Full Perturbation Analysis

Understand

In our previous work \cite{Feng:2013pba}, we have shown a curvaton model where the curvaton has a nonminimal derivative coupling to gravity.

• Such a coupling could bring us scale-invariance of the perturbations for wide range constant values of the equation-of-state of the cosmic background at the early time.
• In this paper, we continue our study by fully analyzing its perturbations up to the third order.
• Apart from the usual 2-point correlation function that has already been calculated in \cite{Feng:2013pba}, we have also taken into account the 3-point correlation functions including pure scalar part, pure tensor part, as well as the cross-correlations between scalar and tensor perturbation modes.