By Harvey Reall
The third law of black hole mechanics asserts that it is impossible for a non-extremal black hole to become extremal in finite time (in classical General Relativity). Counterexamples were found recently: gravitational collapse of a massless charged scalar field can produce an exactly extremal Reissner-Nordstrom black hole in finite time, passing through an intermediate phase in which the solution is exactly Schwarzschild at the horizon. These examples involve matter with a large charge to mass ratio. I will describe how if the charge to mass ratio of matter is suitably bounded then one cannot form an extremal Reissner-Nordstrom black hole in finite time. It is conjectured that one can form an extremal rotating black hole via gravitational collapse of gravitational waves. I will describe recent work showing that this conjecture is true in five spacetime dimensions.
By Donato Bini
By Pierpaolo Mastrolia
By Marie-Anne Bizouard
By Alessandro Nagar
By Simon Maenaut
By Keefe Mitman
By Carlos Lousto
By Simone Albanesi
By Manuela Campanelli
By Marc Henneaux
By Niels Warburton
By Sergiu Klainerman
By Rod Gover
By Jérémie Szeftel
