### Quantum Field Theory for Kerr Black Holes

Recent years have seen a surge of interest in computing classical gravitational observables via scattering-amplitude methods, in the context of binary black-hole systems. Remarkably, Kerr black holes and their gauge-theory counterpart, the root-Kerr solution, were shown to be connected to a special class of amplitudes for massive higher-spin particles. Elegant three-point amplitudes are known for any spin, however constructing the corresponding four-point Compton amplitudes is an open problem. In this talk, I will discuss the origin of the Kerr three-point amplitudes from a higher-spin theory perspective. Guided by higher-spin constraints and classical-limit analysis, I will propose Compton amplitudes relevant for root-Kerr and Kerr to all orders in spin, and discuss their relation to gravitational-wave scattering on Kerr background, as described by black-hole perturbation theory.

**28 November 2023, 14:30**