Cosmological Bootstrap of Kaluza-Klein Gravitons

The cosmological bootstrap program offers new avenues to which theories beyond the Standard Model can be explored and assigned a detectable signature from inflationary dynamics. Motivated by string theory, a candidate for detecting physics beyond the SM are Kaluza-Klein gravitons. These massive exchanges are suppressed by a corresponding Boltzmann factor when the mass is well above the Hubble scale. In this work, we explore a novel mechanism that avoids such a suppression and allows for observable primordial non-Gaussianity mediated by KK gravitons. We compute the precise the magnitude and shape of this non-Gaussianity using cosmological bootstrap techniques.