Quantum gravity lights up spinning black holes

Understand

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.