Zilhao, Miguel, Cardoso, Vitor, Gualtieri, Leonardo, Herdeiro, Carlos, Sperhake, Ulrich and Witek, Helvi (2012), "Dynamics of black holes in de Sitter spacetimes", PHYSICAL REVIEW D, 85, 10.
Abstract: Nonlinear dynamics in cosmological backgrounds has the potential to
teach us immensely about our Universe, and also to serve as prototype
for nonlinear processes in generic curved spacetimes. Here we report on
dynamical evolutions of black holes in asymptotically de Sitter
spacetimes. We focus on the head-on collision of equal mass binaries and
for the first time compare analytical and perturbative methods with full
blown nonlinear simulations. Our results include an accurate
determination of the merger/scatter transition (consequence of an
expanding background) for small mass binaries and a test of the cosmic
censorship conjecture, for large mass binaries. We observe that, even
starting from small separations, black holes in large mass binaries
eventually lose causal contact, in agreement with the conjecture.