Evolution of small-mass-ratio binaries with a spinning secondary

TL;DR

This paper models the evolution and gravitational-wave emission of a spinning compact object inspiraling into a larger black hole, extending previous models to include spin-curvature effects and analyzing waveform dephasing.

Contribution

It introduces a model that incorporates spin-curvature forces for spinning secondary objects in extreme mass ratio inspirals, improving accuracy of waveform predictions.

Findings

Dephasing can be positive or negative depending on initial conditions.

Spin-curvature effects significantly influence waveform phase evolution.

Precession occurs when spin and orbital angular momentum are misaligned.

Abstract

We calculate the evolution and gravitational-wave emission of a spinning compact object inspiraling into a substantially more massive (non-rotating) black hole. We extend our previous model for a non-spinning binary [Phys. Rev. D 93, 064024] to include the Mathisson-Papapetrou-Dixon spin-curvature force. For spin-aligned binaries we calculate the dephasing of the inspiral and associated waveforms relative to models that do not include spin-curvature effects. We find this dephasing can be either positive or negative depending on the initial separation of the binary. For binaries in which the spin and orbital angular momentum are not parallel, the orbital plane precesses and we use a more general osculating element prescription to compute inspirals.