Non-separable Ballooning and Bending Modes of Circumbinary Disks: Mathematical and Plasma Characteristics

Plasma disks associated with binary systems, involving BH in particular, have been shown [1] to sustain oscillatory modes that are ballooning in the vertical direction and bending in the toroidal direction with high mode number. These modes are non-separable in the time (t) and vertical (z) variables and involve mode-particle resonances that depend on the position and are drastically different [2] from the well known wave-particle resonances. In particular, they can interact with two different particle populations and allow for a transfer of energy between the two. This feature could provide an explanation of why high energy radiation emission is not systematically detected in coincidence with the observed coalescence of blackholes assuming that high energy electron populations are produced in the event.

[1] B. Coppi, Culham Campus (U.K.) General Colloquium (24 June 2025).

[2] B. Coppi and B. Basu, Nucl. Fusion 64, 126037 (2024).