Fundamental frequencies and resonances from eccentric and precessing binary black hole inspirals

TL;DR

This paper presents numerical simulations of eccentric, precessing binary black hole inspirals at high mass ratios, analyzing fundamental frequencies, resonances, and eccentricity decay, with implications for gravitational wave modeling.

Contribution

It introduces techniques to extract and compare fundamental frequencies in eccentric, precessing binaries, bridging finite mass-ratio simulations and Kerr geodesic motion.

Findings

Frequency differences align with self-force corrections.

Resonances occur with minimal impact on evolution.

Eccentricity decay matches post-Newtonian predictions.

Abstract

Binary black holes which are both eccentric and undergo precession remain unexplored in numerical simulations. We present simulations of such systems which cover about 50 orbits at comparatively high mass ratios 5 and 7. The configurations correspond to the generic motion of a nonspinning body in a Kerr spacetime, and are chosen to study the transition from finite mass-ratio inspirals to point particle motion in Kerr. We develop techniques to extract analogs of the three fundamental frequencies of Kerr geodesics, compare our frequencies to those of Kerr, and show that the differences are consistent with self-force corrections entering at first order in mass ratio. This analysis also locates orbital resonances where the ratios of our frequencies take rational values. At the considered mass ratios, the binaries pass through resonances in one to two resonant cycles, and we find no discernible effects on the orbital evolution. We also compute the decay of eccentricity during the inspiral and find good agreement with the leading order post-Newtonian prediction.