The gravitational S-matrix from the path integral: asymptotic symmetries and soft theorems

Relations between soft scattering theorems and asymptotic symmetries have revealed additional structure in gravity. The seminar develops a formulation in which the gravitational scattering matrix is extracted from an action or path integral with asymptotic boundary conditions. It compares this approach with holographic generating-function methods and examines the subtleties specific to asymptotically flat spacetime.