Contact Name: Barbara Simoni
Abstract:
The possibility to associate an entropy to eternal black holes is a well established theoretical result. Less understood is the origin of such an entropy in a dynamical context and its tight relationship with the causal horizon. In order to shed some light on this matter, we consider a recent proposal for the definition of gravitational entropy and analyse the thermodynamics of the gravitational field in the simplest homogeneous dust collapse scenario. We are thus able to show that the change in gravitational entropy outside the collapsing body is proportional to the variation of the surface area of the body itself, even before the formation of horizons. As a consequence, the usual Bekenstein-Hawking entropy of the black hole endstate can be related to the build-up of the vacuum entropy outside the body during the collapse.