Collapse of a rapidly differentially rotating supermassive star with a tiny initial m=2 density perturbation. The star is unstable to the non-axisymmetric m=2 mode, collapses, and forms two black holes. The nascent black holes subsequently inspiral and merge under the emission of powerful gravitational radiation. The collapse is accelerated by a ~0.25% reduction in the adiabatic index Gamma, motivated by electron-positron pair production at high temperatures.
Video Credit: 
Simulation & Visualization by Christian Reisswig (Caltech)