PIRSA:21060051

Exotic MOTS, the stability operator and their role in black hole mergers

Booth, I. (2021). Exotic MOTS, the stability operator and their role in black hole mergers. Perimeter Institute. https://pirsa.org/21060051

Booth, Ivan. Exotic MOTS, the stability operator and their role in black hole mergers. Perimeter Institute, Jun. 03, 2021, https://pirsa.org/21060051 

          @misc{ pirsa_PIRSA:21060051,
            doi = {10.48660/21060051},
            url = {https://pirsa.org/21060051},
            author = {Booth, Ivan},
            keywords = {Strong Gravity},
            language = {en},
            title = {Exotic MOTS, the stability operator and their role in black hole mergers},
            publisher = {Perimeter Institute},
            year = {2021},
            month = {jun},
            note = {PIRSA:21060051 see, \url{https://pirsa.org}}
          }

Ivan Booth

Memorial University of Newfoundland

Talk number
PIRSA:21060051
Collection
Talk Type
Subject
Abstract

In the last couple of years it has been demonstrated that black hole spacetimes contain many more marginally outer trapped surfaces (MOTS) than had been previously recognized. For example, there is an infinite family of axially symmetric MOTS even in the Schwarzschild solution, of which the apparent horizon is only the first element. In a recent series of papers (arXiv: 2104.10265, 2104.11343, 2104.11343) we demonstrated that these exotic new MOTS play a key role in black hole mergers and, in fact, are the missing pieces needed to complete the apparent horizon “pair of pants” diagram. This merger turns out to be far richer than that of event horizons and, staying with clothing analogies, is better represented by a rococo ball gown than a pair of pants. 

In this talk, I will overview the techniques that we used to find these surfaces, explain the role played by the exotic MOTS in resolving the merger of apparent horizons during a (head-on, non-rotating) black hole merger and also show how the stability operator brings order to what initially appears to be a chaotic melee of (often self-intersecting!) MOTS as they create, annihilate and weave through time. The stability operator was initially introduced by Andersson, Mars and Simon to characterize when a MOTS will smoothly evolve in time, but I will show that it can also be fruitfully understood as the Jacobi operator for MOTS.