UV Meets the IR: Effective Field Theory Bounds from QFT to String Theory

Coordinators: Patrick Draper, Isabel Garcia Garcia, Yu-tin Huang, and Grant Remmen

A surprising consequence of string theory is that it appears to provide a very large number of possible low-energy laws of physics: the string landscape. The swampland program, the effort to separate this landscape from the swampland of apparently healthy effective field theories that lack a quantum gravitational completion, has been a significant driver of recent high-energy theory research. This top-down approach has resulted in important ideas, such as the Weak Gravity Conjecture, that offer the tantalizing possibility of connecting quantum gravity to the laws of nature at accessible energies. In turn, this presents a unique opportunity for the particle phenomenology community to revisit some of the old assumptions behind the problems of the Standard Model, and offers a concrete path to develop a qualitatively new approach to our understanding of physics in the IR. In parallel, bottom-up, low-energy S-matrix techniques have seen a resurgence in recent years, with many effective field theories being bounded using QFT techniques, including causality, locality, and unitarity. Such first principles bounds, independent of the details of the UV, have recently been applied in a wide variety of settings, including the EFTs of GR and the Standard Model. Supercharging such efforts have been developments in understanding QFT itself, including the modern on-shell amplitudes program and the bootstrap.

From strings to phenomenology to scattering amplitudes, this conference aims to bring together researchers from these varied communities.