Speaker
Description
Positivity bounds derived from unitarity, locality, and causality constrain the Wilson coefficients of EFTs admitting a Lorentz-invariant UV completion. Extending these bounds to the EFT of inflation is nontrivial: cosmological observables are correlation functions rather than scattering amplitudes, the background is quasi–de Sitter rather than Minkowski, and Lorentz invariance is spontaneously broken.
In this talk I will present recent progress in deriving novel positivity bounds on the Wilson coefficients of single-field inflation obtained by combining the flat-space limit of cosmological correlators with the analytic structure of the EFT of inflation as a relativistic superfluid. These results extend the dispersion-relation program to a Lorentz-breaking cosmological background and yield positivity constraints on the inflationary EFT parameter space.