Bootstrapping Multi-Field Inflation: non-Gaussianities from light scalars revisited

Understand

Primordial non-Gaussianities from multi-field inflation are a leading target for cosmological observations, because of the possible large correlations generated between long and short distances.

• These signatures are captured by the local shape of the scalar bispectrum.
• In this paper, we revisit the nonlinearities of the conversion process from additional light scalars into curvature perturbations during inflation.
• We provide analytic templates for correlation functions valid at any kinematical configuration, using the cosmological bootstrap as a main computational tool.