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Black Hole Entropy as Causal Links

Djamel Dou·Rafael D. Sorkin
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Abstract

We model a black hole spacetime as a causal set and count, with a certain definition, the number of causal links crossing the horizon in proximity to a spacelike or null hypersurface $Σ$. We find that this number is proportional to the horizon's area on $Σ$, thus supporting the interpretation of the links as the ``horizon atoms'' that account for its entropy. The cases studied include not only equilibrium black holes but ones far from equilibrium.

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Djamel Dou, Rafael D. Sorkin. 2003-02-03. Black Hole Entropy as Causal Links. https://doi.org/10.1023/a%3A1023781022519

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