Positivity bounds without boosts: New constraints on low energy effective field theories from the UV

We derive new positivity bounds for low-energy effective field theories (EFTs) that are not invariant under Lorentz boosts. ``Positivity bounds'' the manifestation of certain fundamental properties in UV---to date, they have been used to constrain a wide variety EFTs; however, since existing require invariance directly applicable when this symmetry is broken, such as most cosmological and condensed matter systems. Assuming degrees freedom can be extended into UV way consistent with axioms unitarity, analyticity, locality, we an infinite family (derivatives of) $2\ensuremath{\rightarrow}2$ EFT scattering amplitude must satisfy even boosts broken. apply these leading-order both superfluid scalar fluctuations produced during inflation, comparing latter case current observational constraints on primordial non-Gaussianity, demonstrating open window high-energy physics lies beneath our measurements.