Symmetry Breaking in Dynamical Encounters in the Disks of Active Galactic Nuclei

Understand

Active galactic nucleus (AGN) disks may be important sites of binary black hole (BBH) mergers.

• Here we show via numerical experiments with the high-accuracy, high precision code {\tt SpaceHub} that broken symmetry in dynamical encounters in AGN disks can lead to an asymmetry between prograde and retrograde BBH mergers.
• The direction of the hardening asymmetry depends on the initial binary semi-major axis.
• An asymmetric distribution of mass-weighted projected spin $\chi_{\rm eff}$ should therefore be expected in LIGO-Virgo detections of BBH mergers from AGN disks.