In the first part of the talk, I will review constraints on Effective Field Theories that can be derived from first principles of UV completions. I will discuss results that go beyond the famous positivity bounds and I will briefly discuss applications for massive higher spin theories in flat space.
In the second part of the talk, I will discuss causality in gravitational systems beyond the classical limit. The focus will be the time delay in photon scattering against a massive spectator. I will show that the sign of the
INFN & DFA