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On the topology of stationary black holes

P. T. Chrusciel·R. M. Wald
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Abstract

We prove that the domain of outer communication of a stationary, globally hyperbolic spacetime satisfying the null energy condition must be simply connected. Under suitable additional hypotheses, this implies, in particular, that each connected component of a cross-section of the event horizon of a stationary black hole must have spherical topology.

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P. T. Chrusciel, R. M. Wald. 1994-10-05. On the topology of stationary black holes. https://doi.org/10.1088/0264-9381%2F11%2F12%2F001

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