Recent years have seen a surge of progress in post-Minkowskian (PM, weak-field but arbitrary-speed) approximation methods for the gravitational two-body problem, complementing and reorganizing the still much further developed post-Newtonian (PN, weak-field and slow-motion) approximation. This has been driven by simplifying insights, powerful computational tools, and new results coming from the study of on-shell scattering amplitudes in quantum field theories and their classical limits. We will review some of these developments, focusing on the particularly impactful observation (ultimately also understandable from a purely classical perspective but born of the dialog with quantum amplitudes) that certain PM and PN results for arbitrary mass ratios can be determined from surprisingly low orders in the extreme-mass-ratio/self-force expansion.


Talk Number PIRSA:21060052
Speaker Profile Justin Vines