IAS Amplitudes Group Meeting

Abstract: In this work we attempt to understand the analytic structure of amplitudes in theories with broken Lorentz invariance. To this end, we use as an example a UV complete model for relativistic superfluids - a complex scalar theory with quartic interactions at finite density. With a focus on 2 → 2 processes in center-of-mass configurations we find a few interesting properties, including a new branch cut as a result of the theory’s non-analytic dispersion relations. While our results are model-dependent, we hope to understand which of our findings are related to basic physical properties, and how they may be relevant to other Lorentz-breaking systems.