The supermassive black holes which inhabit galactic centers constitute one of the major science targets for gravitational wave physics. Around them, several stellar-mass binaries can be present, forming so called hierarchical triple systems. Recent results in the weak-field regime, indicate these hierarchical triples possess particular waveform signatures that distinguish them from the compact binaries we usually work with.
In a GReCO webinar of the Institut d'Astrophysique de Paris, Francisco extended our understanding of hierarchical triples to the strong-field regime of gravity, showing that these systems can behave as driven harmonic oscillators, where the stellar-mass binaries mimic an external force, and the supermassive black hole is the damped oscillator. As in the undergraduate mechanics problem, when their frequencies match the hierarchical triples exhibit a resonant behavior! Future observations of this and other interesting properties of these systems will help us understand better the non-trivial environments where binaries can evolve and learn more about the extremely complex physics of galactic centers.
