Accretion disks around supermassive black holes are not flat 'pancakes'. Their thickness (the H/R ratio) can vary by a factor of thousands due to different pressure mechanisms (thermal, radiation, magnetic). The authors showed: the frequency of gravitational events (captures, mergers) depends extremely strongly on H/R, falling off as (H/R)⁻⁸. If magnetic fields dominate in the disk, capture rates drop by 10–20 orders of magnitude. This means that to make reliable predictions of cosmic catastrophes, we need to know the actual thickness of these disks.
At the centers of many galaxies lurk supermassive black holes, surrounded by disks of gas, cosmic dust, and stars. Their collisions can spawn gravitational waves—ripples in spacetime. The old picture, developed by Rashid Sunyaev, portrayed this disk as thin and flat, like a packed dance floor: any movement causes a bump.
New research confirms: thickness rules the fate of collisions. Thin disk — cramped, thick disk — empty. Magnetic fields threading the disk can inflate it to enormous sizes, especially in the outer regions. Then, instead of a bustling cosmic mosh pit, near-absolute silence falls.
🎯 If the disk stayed flat like a packed dance floor, collisions would thunder nonstop. But magnetic fields transform it into an empty multi-story atrium, where encounters are almost impossible.