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arXiv · 1508.00355

Uniqueness of photon spheres in electro-vacuum spacetimes

Carla Cederbaum·Gregory J. Galloway
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Abstract

In a recent paper, the authors established the uniqueness of photon spheres in static vacuum asymptotically flat spacetimes by adapting Bunting and Masood-ul-Alam's proof of static vacuum black hole uniqueness. Here, we establish uniqueness of suitably defined sub-extremal photon spheres in static electro-vacuum asymptotically flat spacetimes by adapting the argument of Masood-ul-Alam. As a consequence of our result, we can rule out the existence of electrostatic configurations involving multiple "very compact" electrically charged bodies and sub-extremal black holes.

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Carla Cederbaum, Gregory J. Galloway. 2015-08-04. Uniqueness of photon spheres in electro-vacuum spacetimes. https://doi.org/10.1088/0264-9381%2F33%2F7%2F075006

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