Adiabatic equatorial inspirals of a spinning body into a Kerr black hole

TL;DR

This paper models the influence of a spinning secondary body on gravitational waveforms from EMRIs around Kerr black holes, providing more accurate templates for future gravitational wave detection.

Contribution

It introduces a linearized spin correction to the adiabatic inspiral evolution equations using the Mathisson-Papapetrou-Dixon formalism and Teukolsky fluxes.

Findings

Spin induces measurable phase shifts in gravitational waves.

The model improves waveform accuracy for spinning secondary bodies.

Numerical results quantify the impact of secondary spin on inspiral signals.

Abstract

The detection of gravitational waves from Extreme mass Ratio Inspirals (EMRIs) by the future space-based gravitational-wave detectors demands the generation of accurate enough waveform templates. Since the spin of the smaller secondary body cannot be neglected for the detection and parameter estimation of EMRIs, we study its influence on the phase of the gravitational waves from EMRIs with spinning secondary. We focus on generic eccentric equatorial orbits around a Kerr black hole. To model the spinning secondary object, we use the Mathisson-Papapetrou-Dixon equations in the pole-dipole approximation. Furthermore, we linearize in spin the orbital variables and the gravitational-wave fluxes from the respective orbits. We obtain these fluxes by using the Teukolsky formalism in the frequency domain. We derive the evolution equations for the spin induced corrections to the adiabatic evolution of an inspiral. Finally, through their numerical integration we find the gravitational-wave phase shift between an inspiral of a spinning and a non-spinnig body.