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Black holes, brick walls and the Boulware state

Shinji Mukohyama·Werner Israel
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Abstract

The brick-wall model seeks to explain the Bekenstein-Hawking entropy as a wall-contribution to the thermal energy of ambient quantum fields raised to the Hawking temperature. Reservations have been expressed concerning the self-consistency of this model. For example, it predicts large thermal energy densities near the wall, producing a substantial mass-correction and, presumably, a large gravitational back-reaction. We re-examine this model and conclude that these reservations are unfounded once the ground state---the Boulware state---is correctly identified. We argue that the brick-wall model and the Gibbons-Hawking instanton (which ascribes a topological origin to the Bekenstein-Hawking entropy) are mutually exclusive, alternative descriptions (complementary in the sense of Bohr) of the same physics.

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Shinji Mukohyama, Werner Israel. 1998-06-04. Black holes, brick walls and the Boulware state. https://doi.org/10.1103/physrevd.58.104005

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