Observable signature of magnetic tidal coupling in hierarchical triple systems

2025/10/28 by Marta Cocco, Gianluca Grignani, Cocco, Marta +9 · 4 citations
Biochemistry, Genetics and Molecular Biology · Earth and Planetary Sciences · Engineering · #Characterization and Applications of Magnetic Nanoparticles #Coupling (piping) #Geomagnetism and Paleomagnetism Studies #Noise (video) #Observable #Oceanographic and Atmospheric Processes #Signature (topology) #Spectrum (functional analysis)

paper · pdf · open access · doi:10.1103/84p6-ft3d

published in Physical review. D/Physical review. D. 114(2) (American Physical Society)

openalex publication_date 2026/06/17 · openalex created_date 2026/06/18 · openalex updated_date 2026/08/05

Abstract

We study hierarchical triple systems formed by a compact binary orbiting a supermassive black hole (SMBH), focusing on the role of relativistic magnetic tidal interactions. Extending previous analyses of precession resonances to 0.5 post-Newtonian order, we incorporate quadrupolar magnetic tidal moments, which have no Newtonian counterpart. We find that magnetic tides introduce new resonances absent at lower order, leading to additional eccentricity excitations and significantly modifying the binary’s long-term evolution. Numerical solutions of the Lagrange planetary equations confirm these analytical predictions and reveal how resonance strength depends on orbital eccentricity and inclination. The resulting dynamics accelerates the binary merger and imprints distinctive signatures on gravitational waves, potentially observable by LISA. Our findings identify magnetic tidal coupling as a novel strong-gravity effect and establish its importance for the resonant dynamics of compact-object binaries near SMBHs.

Cited by

• Tidal perturbations of an extreme mass ratio inspiral around a Kerr black hole
• Ringdown and lensing of triple systems
• Periodic line-of-sight velocity-driven modulations to gravitational waves emitted by compact binaries in Keplerian outer orbits
• Gravitational waves from the late inspiral, transition, and plunge of small-mass-ratio eccentric binaries

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