2021/04/30 by Daniel Pook-Kolb, Robie A. Hennigar, Ivan Booth
Mathematics · Physics and Astronomy · #Apparent horizon #Arithmetic #Astronomy #Binary number #Black Holes and Theoretical Physics #Black hole (networking) #Classical mechanics #Computer science #Cosmology and Gravitation Theories #Event horizon #Horizon #Mathematics #New horizons #Physics #Pulsars and Gravitational Waves Research #Stability (learning theory) #Theoretical physics #gr-qc
paper · pdf · doi:10.1103/physrevlett.127.181101
published as Phys. Rev. Lett. 127, 181101 (2021) · 6 pages, 5 figures, V2: final version with several changes (including changed title)
openalex publication_date 2021/10/25 · arxiv created 2021/11/16 · arxiv updated 2021/11/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We resolve the fate of the two original apparent horizons during the head-on merger of two nonspinning black holes. We show that, following the appearance of the outer common horizon and subsequent interpenetration of the original horizons, they continue to exist for a finite period of time before they are individually annihilated by unstable marginally outer trapped surfaces (MOTSs). The inner common horizon vanishes in a similar, though independent, way. This completes the understanding of the analog of the event horizon's "pair of pants" diagram for the apparent horizon. Our result is facilitated by a new method for locating MOTSs based on a generalized shooting method. We also discuss the role played by the MOTS stability operator in discerning which among a multitude of MOTSs should be considered as black hole boundaries.