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Friday, February 28, 2025
11:00 AM - 12:00 PM
Online and In-Person Event

High Energy Theory Seminar

Where is tree-level string theory?
Leonardo Rastelli, Stony Brook University,

String theory extends Einstein gravity by an infinite set of massive higher spin particles. From a purely spacetime perspective (if we didn't know about the worldsheet picture) the consistency of tree-level string amplitudes would appear truly miraculous. This prompts the question: is string theory the unique framework for a higher spin extension of gravity?  We investigate this question by bootstrap methods, focussing on maximal 10D supergravity. We parametrize theory space by the first few EFT coefficients and by the on-shell coupling of the lightest massive state, and impose on these data causality and positivity constraints. While Type II string theory lives strictly inside the allowed region, we uncover a novel extremal solution of the bootstrap problem, which appears to contain a single linear Regge trajectory. We repeat a similar analysis for supergluon scattering.

The talk is in 469 Lauritsen.

Contact theoryinfo@caltech.edu for Zoom information.