The information recovery problem
  The issue of unitary evolution during creation and evaporation of a black hole remains controversial. We~argue that some prominent cures are more troubling than the disease, demonstrate that their central element---forming of the event horizon before the evaporation begins---is not necessarily true, and describe a fully coupled matter-gravity system which is manifestly unitary. 
Valentina Baccetti, Viqar Husain, Daniel R. Terno
gr-qc hep-th