In flat space, symmetries and singularities completely fix the structure of scattering amplitudes at weak coupling. For example, four-particle amplitudes are analytic for contact interactions and have simple poles with positive residues for tree-level exchange. In this colloquium, I will describe a new understanding of inflationary correlation functions that parallels this understanding of flat-space scattering amplitudes. The material will be presented in a way that should be accessible to a broad audience.
The talk will be based on work to appear with Nima Arkani-Hamed, Hayden Lee and Guilherme Pimentel.
