The fate of chaotic binaries

TL;DR

This paper explores how chaotic precession in stellar-mass black hole binaries affects gravitational wave signals, highlighting the dependence on mass ratio, spins, and eccentricity, and its implications for detection.

Contribution

It demonstrates that chaotic precession can cause irregular gravitational wave modulations, with the effect depending on spins, mass ratio, and eccentricity, providing insights for gravitational wave detection.

Findings

Chaotic precession causes irregular gravitational wave modulations.

Spin magnitudes and misalignments significantly influence chaos.

Eccentricity is not essential for chaos to occur.

Abstract

A typical stellar mass black hole with a lighter companion is shown to succumb to a chaotic precession of the orbital plane. As a result, the optimal candidates for the direct detection of gravitational waves by Earth based interferometers can show irregular modulation of the waveform during the last orbits before plunge. The precession and the subsequent modulation of the gravitational radiation depends on the mass ratio, eccentricity, and spins. The smaller the mass of the companion, the more prominent the effect of the precession. The most important parameters are the spin magnitudes and misalignments. If the spins are small and nearly aligned with the orbital angular momentum, then there will be no chaotic precession while increasing both the spin magnitudes and misalignments increases the erratic precession. A large eccentricity can be induced by large, misaligned spins but does not seem to be required for chaos. An irregular precession of the orbital plane will generate irregularities in the gravitational wave frequency but may have a lesser effect on the total number of cycles observed.