Precession resonances in hierarchical triple systems

TL;DR

This paper introduces a new precession resonance in relativistic hierarchical triple systems, which can significantly increase binary eccentricity even under dominant relativistic precession, affecting gravitational wave observations.

Contribution

It identifies and analyzes a novel resonance mechanism in relativistic triples, expanding understanding of their dynamical behavior and observational implications.

Findings

Precession resonance can exponentially increase binary eccentricity.

Resonance occurs when relativistic precession period matches a distant perturber's period.

The resonance depends mainly on three key parameters.

Abstract

We describe a new kind of resonance occuring in relativistic three-body hierarchical systems: the precession resonance, occuring when the relativistic precession timescale of a binary equals the period of a distant perturber. We find that, contrary to what most previous studies assume, it can lead to an exponential increase of eccentricity of the binary even when relativistic precession dominates the quadrupolar perturbation. The resonance may happen in the observation band of LISA or change the eccentricity distribution of triples. We discuss the physics of the resonance, showing that it mainly depends on three parameters.