HIDDeN & ASYMMETRY WEBINAR: Tuesday 7th November 2023 @16:00 (CET)
Speaker: Kevin Zhou (Stanford University)
Title: Electromagnetism and Gravity with Continuous Spin.
Abstract: Powerful general arguments allow only a few families of long-range interactions, exemplified by gauge field theories of electromagnetism and gravity. However, all of these arguments presuppose that massless fields have zero spin scale and hence a single boost invariant helicity. I will present a Lagrangian formalism describing interactions of matter particles with bosonic "continuous spin" fields with nonzero spin scale, and thereby an infinite number of helicity modes. Remarkably, physical observables such as forces and radiation emission are well approximated by familiar theories in the ultraviolet, with calculable, universal, and observable deviations at low frequencies and long distances. Furthermore, scattering amplitudes feature novel, nontrivial analytic structures which ensure they remain finite and unitary. These infrared modifications to familiar forces, long thought impossible, may shed light on the hierarchy and cosmological constant problems.