Detectors in black hole quantum coherent states

The corpuscular model describes black holes as leaky bound states of gravitons. To account for the role of matter, a coherent state is built and a semiclassical description is given to the gravitational field by connecting the classical source with the quantum state for gravitons. The properties of this state can be analysed with the help of an Unruh-DeWitt detector, coupled to the quantum state of the system. The presence of a detector in general regularises the usual diverging behaviour of the field in the deep ultraviolet region, and will allow us to probe the coherent state structure and the graviton emission. In particular, a Newtonian analogue of the Unruh effect will be discussed and the coherent state will be modified to properly account for the spherical symmetry of the potential at the level of the quantum state. This correction will ensure that vacuum contributions responsible for the Unruh thermal spectrum are present in a coherent state emission process.