Bootstrapping Supergraviton Amplitudes

by Waltraut Knop (DESY)

Tuesday 17 Nov 2026, 14:00 → 15:00 Europe/Zurich

4/2-037 - TH meeting room (CERN)

Which features of string theory are required by the consistency of quantum gravity? In this talk, we consider this question in the setting of tree-level graviton scattering in ten dimensions with (half-)maximal supersymmetry. Rather than assuming a particular UV completion, we impose general principles of S-matrix consistency, including unitarity, causality, Regge behavior, and crossing, and determine the resulting constraints on the low-energy EFT. We find that both Type II and heterotic string theories arise as consistent points in the allowed space. The extremal amplitudes, i.e. those on the boundary of the allowed region, are characterised by single Regge trajectories, a remarkably stringy feature!