HET Seminar | Bounds on effective theories of gravity

Note Special Time Tuesday 12 noon - 1 PM

Modifications of Einstein’s theory of gravity can be systematically analyzed using the framework of effective field theory (EFT). In this setup, new physics is captured in a set of higher-dimension operators whose coefficients must be measured experimentally, or matched from a UV completion. It has been known for some time that basic principles, such as unitarity and causality, impose constraints on the allowed values of such coefficients, but a framework to exhaustively explore said constraints has only emerged recently. In this talk I will explain how developments in scattering amplitudes and the conformal bootstrap allowed us to compute sharp numerical bounds on these EFT coefficients. Our results have direct implications for the possibility of testing modifications of General Relativity using gravitational waves and in other astrophysical settings. In addition they also connect with the swampland program. Finally, I will briefly comment on the possibility of obtaining similar results for the Standard Model Effective Theory (SMEFT).