Higher-spin effects in black hole and neutron star binary dynamics: worldline supersymmetry beyond minimal coupling

TL;DR

This paper develops a novel method extending worldline supersymmetry beyond minimal coupling to accurately model higher-spin effects in binary black hole and neutron star systems, improving gravitational wave predictions.

Contribution

It introduces a new approach to incorporate higher-order spin effects in binary dynamics by extending supersymmetry beyond minimal coupling, enabling all-order in spin calculations.

Findings

Derived a supersymmetric Hamiltonian valid to all orders in spin and linear in curvature.

Constructed a cubic order in spin Hamiltonian in arbitrary dimensions.

Demonstrated exponentiation of three-point and Compton amplitudes using the Generalized Wilson line.

Abstract

The inclusion of spin effects in the binary dynamics for black hole and neutron stars is crucial for the computation of gravitational wave observables. Worldline supersymmetric models have shown to be particularly efficient at this task up to quadratic order in spin, but progress at higher orders has been hampered by no-go-theorems. In this work we propose a novel approach to overcome this problem by extending the supersymmetry beyond minimal coupling. We demonstrate the potential of this approach by computing an all-order in spin and linear in curvature, manifestly supersymmetric Hamiltonian, as well as a cubic order in spin Hamiltonian in arbitrary spacetime dimensions. In doing so, we identify a criterion that uniquely determines the Kerr geometry in terms of worldline supersymmetry. Equipped with these Hamiltonians, we demonstrate the exponentiation of three-point and Compton amplitudes using the recently proposed Generalized Wilson line approach.