arXiv:2306.11454·v2·High Energy Physics — Theory
The Relation Between KMOC and Worldline Formalisms for Classical Gravity
Poul H. Damgaard🇩🇰 · Elias Roos Hansen🇩🇰 · Ludovic Planté🇩🇰 · Pierre Vanhove🇫🇷
Abstract
We demonstrate the equivalence between KMOC and worldline formalisms for classical general relativity, highlighting how the Keldysh-Schwinger in-in formalism is contained in both of them even though the KMOC representation conventionally leads to the evaluation of scattering amplitudes with Feynman propagators. The relationship between the two approaches is illustrated in detail for the momentum kick at second Post-Minkowskian order.
Comments: 39 pages. v2: Some clarifications and references added. Version to appear in JHEP