Black holes can split in two — but only if they spin at extreme speeds

New research suggests that black holes, under extreme conditions, may split into two separate entities, challenging the long-held belief that black holes only merge. The study, published in Physical Review Letters, reveals that a single black hole can fission if it spins at nearly the maximum possible rate. This process, analogous to nuclear fission, occurs when rotational energy overcomes gravitational binding. The findings imply that black hole populations could be more diverse than previously thought, with high-spin black holes potentially producing pairs of smaller black holes. This could explain the existence of intermediate-mass black holes and affect gravitational wave signals from mergers. The research opens new avenues for understanding black hole formation and evolution in the universe. Future observations with gravitational wave detectors may test these predictions.