Black Hole Non-Formation in Braneworld

We begin by showing that a collapsing dust cloud with a central homogeneous core must have a faint atmosphere in the Brane-World, unlike the four-dimensional General Relativistic case, in which a pure vacuum exterior is allowed. Assuming a diagonal five dimensional metric, we then find the conditions for which the collapsing object generically "evaporates" during the collapse and we show that the emitted flux approaches the Hawking behavior as the (apparent) horizon is being formed, hence giving an holographic interpretation of the quantum evaporation process of a four-dimensional black hole. Subsequently, as the apparent horizon evolves into the atmosphere, the back-reaction on the brane metric reduces the evaporation, which continues until the energy of the star vanishes. This occurs at a finite radius, and the dust star afterwards re-expands and "anti-evaporates" back into the state it started from.