Primordial non-Gaussianity from two curvaton decays

Understand

We study a model where two scalar fields, that are subdominant during inflation, decay into radiation some time after inflation has ended but before primordial nucleosynthesis.

• Perturbations of these two curvaton fields can be responsible for the primordial curvature perturbation.
• We write down the full non-linear equations that relate the primordial perturbation to the curvaton perturbations on large scales, calculate the power spectrum of the primordial perturbation, and finally go to second order to find the non-linearity parameter, fNL.
• We find large positive values of fNL if the energy densities of the curvatons are sub-dominant when they decay, as in the single curvaton case.