<< Binary black holes are basically like giant targets hanging out in the cluster, and as you throw other black holes or stars at them, they undergo these crazy chaotic encounters >>
<< What people had done in the past was to treat this as a purely Newtonian problem, (..) Newton’s theory of gravity works in 99.9 percent of all cases. The few cases in which it doesn’t work might be when you have two black holes whizzing by each other very closely, which normally doesn’t happen in most galaxies >> Carl Rodriguez
Jennifer Chu. Dense stellar clusters may foster black hole megamergers. MIT News Office. Apr 10, 2018.
http://news.mit.edu/2018/dense-stellar-clusters-may-foster-black-hole-megamergers-0410
Carl L. Rodriguez, Pau Amaro-Seoane, et al. Post-Newtonian Dynamics in Dense Star Clusters: Highly-Eccentric, Highly-Spinning, and Repeated Binary Black Hole Mergers.
Phys. Rev. Lett. 120, 151101 (2018). doi: 10.1103/PhysRevLett.120.151101.
arXiv:1712.04937 [astro-ph.HE]. Mar 14, 2018