Origin of Hawking radiation: firewall or atmosphere?
The Unruh vacuum not admitting any outgoing flux at the horizon implies that the origin of the outgoing Hawking radiation is the atmosphere of a near-horizon quantum region without resort to the firewall; however, the existence of the firewall of superplanckian excitations at the horizon can be supported by the infinite Tolman temperature at the horizon. In an exactly soluble model, we explicitly show that the firewall necessarily emerges out of the Unruh vacuum so that the Tolman temperature in the Unruh vacuum is divergent in essence due to the infinitely blueshifted negative ingoing flux crossing the horizon rather than the outgoing flux. We also show that the outgoing Hawking radiation in the Unruh vacuum indeed originates from the atmosphere, not just at the horizon, which is of no relevance to the infinite blueshift. Consequently, the firewall from the infinite Tolman temperature and the Hawking radiation from the atmosphere turn out to be compatible, once we waive the claim that the Hawking radiation in the Unruh vacuum originates from the infinitely blueshifted outgoing excitations at the horizon.
KeywordsBoulware vacuum Israel-Hartle-Hawking vacuum Unruh vacuum Tolman temperature Stefan-Boltzmann law Firewall
I have benefited from discussions with M. Eune, Y. Gim, and E. J. Son, and especially thank W. Israel for introducing his helpful paper for improvement of the present work.
- 8.Susskind, L.: Singularities, Firewalls, and Complementarity. [arXiv:1208.3445]
- 9.Hossenfelder, S.: Comment on the Black Hole Firewall. [arXiv:1210.5317]
- 12.Hutchinson, J., Stojkovic, D.: Icezones Instead of Firewalls: Extended Entanglement Beyond the Event Horizon and Unitary Evaporation of a Black Hole. [arXiv:1307.5861]
- 15.Unruh, W.G.: Dumb holes and the effects of high frequencies on black hole evaporation. [arXiv:gr-qc/9409008]
- 17.Israel, W.: Shenanigans at the Black Hole Horizon: Pair Creation or Boulware Accretion? [arXiv:1504.02419]
- 34.Hawking, S.W.: Information preservation and weather forecasting for black holes. [arXiv:1401.5761]
- 37.Mersini-Houghton, L., Pfeiffer, H.P.: Back-Reaction of the Hawking Radiation Flux on a Gravitationally Collapsing Star II. [arXiv:1409.1837]
- 38.Nomura, Y., Salzetta, N.: Why Firewalls Need Not Exist. [arXiv:1602.07673]