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Dynamic black-hole entropy

Sean A. Hayward·Shinji Mukohyama·M. C. Ashworth
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Abstract

We consider two non-statistical definitions of entropy for dynamic (non-stationary) black holes in spherical symmetry. The first is analogous to the original Clausius definition of thermodynamic entropy: there is a first law containing an energy-supply term which equals surface gravity times a total differential. The second is Wald's Noether-charge method, adapted to dynamic black holes by using the Kodama flow. Both definitions give the same answer for Einstein gravity: one-quarter the area of the trapping horizon.

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Sean A. Hayward, Shinji Mukohyama, M. C. Ashworth. 1998-10-02. Dynamic black-hole entropy. https://doi.org/10.1016/s0375-9601(99)00225-x

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