A worldsheet for Kerr

Abstract

We show that the Newman-Janis shift property of the exact Kerr solution can be interpreted in terms of a worldsheet effective action. This holds both in gravity, and for the single-copy $\sqrt{\text{Kerr}}$ solution in electrodynamics. At the level of equations of motion, we show that the Newman-Janis shift holds also for the leading interactions of the Kerr black hole. These leading interactions are conveniently described using chiral classical equations of motion with the help of the spinor-helicity method familiar from scattering amplitudes.

18 pages + appendices + references, 1 figure; v3: minor corrections, journal version

References in corpus (7)

• Scattering Amplitudes and the Conservative Hamiltonian for Binary Systems at Third Post-Minkowskian Order
• Black holes and the double copy
• Gravitational scattering, post-Minkowskian approximation and Effective One-Body theory
• Energetics of two-body Hamiltonians in post-Minkowskian gravity
• Leading order finite size effects with spins for inspiralling compact binaries
• Kerr-Newman from Minimal Coupling
• Tidal effects for spinning particles