Scattering of spinning compact objects from a worldline EFT

Understand

We study the EFT of a spinning compact object and show that with appropriate gauge fixing, computations become amenable to worldline quantum field theory techniques.

• We use the resulting action to compute Compton and one-loop scattering amplitudes at fourth order in spin.
• By matching these amplitdes to solutions of the Teukolsky equations, we fix the values of Wilson coefficients appearing in the EFT such that it reproduces Kerr black hole scattering.
• We keep track of the spin supplementary condition throughout our computations and discuss alternative ways to ensure its preservation.