A Note on trapped Surfaces in the Vaidya Solution
arXiv:0809.2213 · doi:10.1103/PhysRevD.79.024027
Abstract
The Vaidya solution describes the gravitational collapse of a finite shell of incoherent radiation falling into flat spacetime and giving rise to a Schwarzschild black hole. There has been a question whether closed trapped surfaces can extend into the flat region (whereas closed outer trapped surfaces certainly can). For the special case of self-similar collapse we show that the answer is yes, if and only if the mass function rises fast enough.
14 pages, 4 figures; minor polish added to version 2