IAS Amplitudes Group Meeting

Abstract: Dispersion relations for four-point scattering amplitudes explicitly display how the particle content of a theory affects its physical observables and highlight how physical requirements like unitarity, causality, and locality place constraints on amplitudes. In my talk, I will describe how analyzing these dispersion relations allows us to find two-sided bounds on the masses of hadrons in large-N QCD, identify field-theoretic input which makes the open superstring the unique tree-level UV completion of maximally supersymmetric Yang-Mills, and completely map uncolored identical scalar theories with a one-parameter family of “extremal” amplitudes.