Würzburg Seminar on Quantum Field Theory and Gravity

Gravitational effective field theories are highly constrained by unitarity, causality, crossing symmetry, and Regge behavior. I will describe recent progress in turning these principles into quantitative bounds using stringy dispersion relations. The talk will focus on bounds on graviton EFT Wilson coefficients, Newton’s constant in cutoff units, and higher-spin spectral residues. I will explain how the numerical bootstrap reproduces known gravitational positivity bounds, how new spectral diagnostics reveal Regge-like structure in extremal solutions, and how controlled higher-spin strength can affect the allowed hierarchy between the EFT and Planck scales. The broader aim is to show that dispersion relations provide not only consistency tests, but also a practical map of the space of gravitational EFTs.