Primordial Trispectrum from Isocurvature Fluctuations

Understand

We study non-Gaussianity generated by adiabatic and isocurvature primordial perturbations.

• We first obtain, in a very general setting, the non-linear perturbations, up to third order, for an arbitrary number of cosmological fluids, going through one or several decay transitions.
• We then apply this formalism to the mixed curvaton and inflaton model, allowing for several decay channels.
• We compute the various contributions to the bispectrum and trispectrum resulting from adiabatic and isocurvature perturbations, which are correlated in general.