Multipoint Correlators in Multifield Cosmo.: structure & applications -- Eva Silverstein (Stanford)

Multipoint Correlators in Multifield Cosmology: formal structure and applications -- Eva Silverstein (Stanford)

Connected N-point amplitudes in quantum field theory are enhanced by a factor of N! in appropriate regimes of kinematics and couplings, but the non-perturbative analysis of this for collider physics applications is subtle. We will start by briefly reviewing this effect and related developments in large-charge sectors of quantum field theory. We then resolve the question in the affirmative for N-point correlation functions of cosmological perturbations in multifield inflation, and comment on its application to primordial non-Gaussianity. We find that they are calculably N!-enhanced using a simple model for the mixing of the field sectors which leads to a convolution of their probability distributions. This effect leads to model-dependent but interesting prospects for enhanced observational sensitivity. Additional spinoffs include applications to primordial black hole production and a new inflationary model with a controlled resummation of derivative interactions.