|Title:||Gravity: The force from the UV|
Does our world respect causality at all energy scales? We explore constraints on low-energy dynamics which stem from this assumption. Obstructions to a causal UV completion can be diagnosed using dispersive sum rules, which connect the infrared and ultraviolet. While dispersion relations originate in optics and quantum field theory, I will argue that their true purpose is gravity, where they become particularly powerful due to the maximal growth rate of this force with energy. This leads, technically, to the so-called graviton pole in sum rules. I will briefly review how, for non-gravitational low-energy effective theories, causality turns dimensional analysis estimates into sharp numerical bounds, and I will present initial results on gravitational effective theories.