Binary dynamics from worldline QFT for scalar QED

Abstract

We investigate the worldline quantum field theory (WQFT) formalism for scalar QED and observe that a generating function emerges from WQFT, from which the scattering angle ensues. This generating function bears important similarities to the radial action in that it requires no consideration of exponentiation of lower-order contributions. We demonstrate the computations of this generating function and the resulting scattering angle of a binary system coupled to an electromagnetic field up to the third order in the post-Minkowskian expansion.