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arXiv · 2206.11152

Quantum gravity lights up spinning black holes

Astrid Eichhorn·Aaron Held
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Abstract

Quantum-gravity effects in black holes are generally expected to be unobservable if they set in at transplanckian curvature scales. Here, we challenge this expectation. A near-critical spin parameter can serve as a lever arm that translates Planckian quantum-gravity effects to a global change in the spacetime: the horizon dissolves and the black hole "lights up". We investigate this transition between a black hole and a horizonless spacetime and find that additional lensing features appear instantaneously, when the quantum-gravity effect is added. In the presence of an accretion disk, a second set of internal photon rings appears in addition to the exponentially stacked set of external photon rings. The internal and external photon rings merge into cresent-like features as a function of increasing spin parameter. We explore how these simulated images would be reconstructed by a radio-very-long-baseline-interferometry array like the Event Horizon Telescope. We find that a future next-generation Event Horizon Telescope may be sensitive to the additional lensing features.

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Astrid Eichhorn, Aaron Held. 2022-06-22. Quantum gravity lights up spinning black holes. https://doi.org/10.1088/1475-7516%2F2023%2F01%2F032

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