Resonant Locking Between Binary Systems Induced by Gravitational Waves

TL;DR

This paper explores a novel resonant interaction mechanism where gravitational waves from a background binary can synchronize with a foreground binary, significantly affecting their evolution and merger times in galaxies.

Contribution

It introduces the concept of gravitational wave-induced resonant locking between binary systems, a previously unconsidered dynamical phenomenon with implications for binary evolution.

Findings

Up to 30 binaries can become resonantly locked in a galaxy.

Resonant locking can significantly reduce binary merger times.

Approximately 10 billion binaries may have experienced locking historically.

Abstract

The interaction of gravitational waves (GWs) with matter is thought to be typically negligible in the Universe. We identify an exception in the case of resonant interactions, where GWs emitted by a background binary system, such as an inspiraling supermassive black hole (SMBH) binary, cause a resonant response in a stellar-mass foreground binary and the frequencies of the two systems become, and remain, synchronized. We point out that this previously unexplored dynamical phenomenon is not only possible, but can lead to $\mathcal{O}(30)$ binary systems becoming resonantly locked in the host galaxy of merging SMBHs of mass $10^{8.5-11}\Msun$, each of which has a significantly reduced merger time. We predict $\mathcal{O}(10^{10})$ binary systems have been locked in the Universe's history. Resonant locking could be detected through anomalous inspiral of binary systems.