Non-Gaussianity in the modulated reheating scenario

Abstract

We investigate the non-Gaussianity of primordial curvature perturbation in the modulated reheating scenario where the primordial perturbation is generated due to the spacial fluctuation of the inflaton decay rate to radiation. We use the $\delta N$ formalism to evaluate the trispectrum of curvature perturbation as well as its bispectrum. We give expressions for three non-linear parameters $f_{NL},{\tau }_{NL}$ and $g_{NL}$ in the modulated reheating scenario. If the intrinsic non-Gaussianity of scalar field fluctuations and third derivative of the decay rate with respect to scalar fields are negligibly small, $g_{NL}$ has at least the same order of magnitude as $f_{NL}$. We also give general inequality between $f_{NL}$ and ${\tau }_{NL}$ which is true for other inflationary scenarios as long as primordial non-Gaussianity comes from super-horizon evolution.

references added

References in corpus (1)

• Primordial non-Gaussianity from two curvaton decays

Cited by in corpus (3)

• Primordial Curvature Fluctuation and Its Non-Gaussianity in Models with Modulated Reheating
• Non-Gaussianity, Spectral Index and Tensor Modes in Mixed Inflaton and Curvaton Models
• Modulated Perturbations from Instant Preheating after new Ekpyrosis