From Scattering Amplitudes to Black Holes

概要

Recently, there has been growing attention to applying quantum field-theoretic techniques, such as scattering amplitudes, to problems of classical gravity. It has led to the highest precision calculations of gravitational two-body systems, refined connections between classical and quantum physics, and a novel perspective on black holes. In this talk, we push forward this program to understand the physics of black holes, especially their horizons, at both classical and quantum levels. Central to this is the mass-changing amplitude, where a black hole transitions to a different mass state by absorption or emission. We discuss that this amplitude correctly describes mergers of two black holes, the horizon absorption of gravitational waves, and even the Hawking radiation, and serves as the building block for computing various observables of black holes.