Speaker
Description
Motivated by the success story of the modern S-matrix bootstrap in mapping out the space of scattering amplitudes consistent with fundamental principles, I explore how a similar framework can be applied to cosmological correlators generated during inflation. In particular, I focus on the bispectrum of curvature perturbations sourced by interactions with a generic hidden sector during inflation, and I show that the result must obey a set of positivity constraints stemming from the interplay between unitarity and de Sitter isometries. While I assume certain broad features of the hidden sector, I remain agnostic about its microscopic details. As a result, the derived positivity bounds are broadly applicable to a wide range of inflationary UV completions—whether the bispectrum arises from the exchange of weakly coupled fields, such as Kaluza-Klein modes or moduli in extra-dimensional models, or from operators with continuous spectra, as in conformal field theories.
