Enhanced tensor non-Gaussianities in presence of a source

Abstract

We address the possibility of having an enhanced signal for tensor non-Gaussianities in presence of a source, as a signature of Primordial Gravitational Waves. We employ a nearly model-independent framework based on Effective Field Theory of inflation and compute tensor non-Gaussianities therefrom sourced by particle production during (p)reheating to arrive at an enhanced signal strength. We obtain the model-independent non-linearity parameters and also find that squeezed limit bispectra are more enhanced than equilateral limit.