  Scattering angles for probes in Kerr metrics are derived for scattering in
the equatorial plane of the black hole. We use a method that naturally resums
all orders in the spin of the Kerr black hole, thus facilitating comparisons
with scattering-angle computations based on the Post-Minkowskian expansion from
scattering amplitudes or worldline calculations. We extend these results to
spinning black-hole probes up to and including second order in the probe spin
and any order in the Post- Minkowskian expansion, for probe spins aligned with
the Kerr spin. When truncating to third Post-Minkowskian order, our results
agree with those obtained by amplitude and worldline methods.

High Energy Physics - Theory;General Relativity and Quantum Cosmology