The thermodynamics of “horizon brightened acceleration radiation” (HBAR), due to a random atomic cloud freely falling into a black hole in a Boulware-like vacuum, is shown to mimic the thermodynamics of the black hole itself. The thermodynamic framework is developed in its most general form via a quantum-optics master equation, including rotating (Kerr) black holes and for any set of initial conditions of the atomic cloud. The HBAR field exhibits thermal behavior at the Hawking temperature and an area-entropy-flux relation that resembles the Bekenstein-Hawking entropy. In addition, this general approach reveals: (i) the existence of an HBAR-black-hole thermodynamic correspondence that explains the HBAR area-entropy-flux relation; (ii) the origin of the field entropy from the near-horizon behavior, via conformal quantum mechanics (CQM).

• Received 18 August 2021
• Accepted 21 September 2021

DOI:https://doi.org/10.1103/PhysRevD.104.084085