Black holes can split in two, but only at near-maximum spin

Researchers at the University of Naples Federico II found that a single black hole can split into two if it spins close to its maximum possible rate. The study was published Oct. 22 in Physical Review D; the probability of such a split is not yet quantified.

• Splitting requires spin close to the maximum possible rate
• The event horizon divides in a "pair-of-pants" topology
• A split is likelier when one resulting black hole is much smaller
• Gamma-ray telescopes such as Fermi-LAT could spot indirect signals