Speaker
Description
We will show how scattering orbits can inform bound-orbit models, allowing to harness the power of the S-matrix to construct gravitational waveforms relevant for the dynamics of compact binary systems. First, I will derive the radial action from the worldline formalism, focusing for simplicity on the probe limit in a Kerr background. Then, I will show that such radial action (and the S-matrix) is a natural generating functional of classical observables, which provide a direct analytic continuation between a novel on-shell basis of scattering (time delay, elapsed proper time and deflection angle) and bound (radial frequency, averaged redshift and periastron advance) observables. Including radiation, we will then derive a new surprising map between scattering and bound waveforms, which is inspired and confirmed by Post-Newtonian calculations with time-domain multipoles. Finally, I will discuss some ongoing effort in trying to extend this map at 1SF order (with non-local-in-time hereditary effects) order using a novel geometric approach to the scattering-to-bound dictionary.
