DESY Theory Seminar

A Post-Minkowskian EFT for the Gravitational Two-Body Problem

by Gregor Kaelin (DESY)




I will discuss an effective field theory (EFT) of two massive gravitationally interacting bodies in a world-line formalism. While the conservative potential is usually the sought-after quantity, we instead use the radial action as a central quantity. From this gauge-invariant object all other desirable observables (and the potential) for the binary inspiral problem can be easily derived. From the EFT perspective, the radial action, as a Post-Minkowskian expansion in G, can be obtained from the scattering angle via an analytic continuation in angular momentum and energy. I will demonstrate the derivation of the scattering angle and how the whole network of related quantities for the bound problem is obtained via this simple analytic continuation.