Special Cosmo Journal Club talk: "Cosmological Collider as an Interaction Probe: Scale-dependence and Diagrams"

Massive fields can imprint unique oscillatory features on primordial correlation functions or inflationary correlators, which is dubbed the cosmological collider signal. Previous works have especially revealed that the masses of isocurvature modes are uniquely determined. However, the distinction of other characteristics of particles, such as their spin, charge, and interactions, is still being studied. In this talk, I will discuss several aspects of identifying interactions from cosmological collider signals. My discussion is based on two papers: the first, 2312.09642, addresses the scale dependence induced by non-shift-symmetric interactions, and the second, 2404.09547, presents an exact calculation of a diagram involving double massive intermediate particles.