Classical Double Copy of Worldline Quantum Field Theory

Understand

The recently developed worldline quantum field theory (WQFT) formalism for the classical gravitational scattering of massive bodies is extended to massive, charged point particles coupling to bi-adjoint scalar field theory, Yang-Mills theory, and dilaton-gravity.

• We establish a classical double copy relation in these WQFTs for classical observables (deflection, radiation).
• The bi-adjoint scalar field theory fixes the locality structure of the double copy from Yang-Mills to dilaton-gravity.
• Using this the eikonal scattering phase (or free energy of the WQFT) is computed to next-to-leading order (NLO) in coupling constants using the double copy as well as directly finding full agreement.