Quantum Gravity Seminar: Henriette Elvang

Speaker: Henriette Elvang (University of Michigan)

Title: Non-SUSY S-matrix Bootstrap from Maximally SUSY

Abstract: In the talk I'll discuss the S-matrix bootstrap applied to a very elementary set up, namely to Effective Field Theories (EFTs) of a single massless scalar field. I will briefly review how dispersion relations and positivity gives two-sided bounds on the Wilson coefficients. I will then characterize the amplitudes of the "extremal theories" that determine the universal bounds on the Wilson coefficients of the general non-supersymmetric EFTs. Then I will argue that the extremal theories are in one-to-one correspondence with a maximally supersymmetric extremal theory and I will give the precise map between them. This means that the universal bounds on the non-susy EFT can be obtained from the bounds of maximally SUSY EFTs. Finally I'll discuss bootstrapping the 4-point amplitudes of the open superstring Dirac-Born-Infeld  and of the closed string Virasoro-Shapiro amplitudes.  

Zoom Link: https://ucph-ku.zoom.us/j/9295289933?omn=67282578176