A rotating GUP black hole: metric, shadow, and bounds on quantum parameters

TL;DR

This paper derives a rotating quantum-inspired black hole metric, analyzes its properties, and uses observational data to constrain quantum parameters and black hole spin limits.

Contribution

It extends a static quantum black hole metric to a rotating case using Newman-Janis, revealing new singularity features and observational bounds.

Findings

Rotation introduces singularities not present in the static case

Quantum parameters affect horizon, temperature, and entropy

Bounds on quantum parameters and black hole spin from EHT data

Abstract

Recently, for the first time, a metric of a static spherically symmetric generalized uncertainty inspired quantum black hole was derived. We apply the modified Newman-Janis algorithm to this metric and derive its rotating counterpart. We show that this metric has all the correct limits, while due to Newman-Janis side effects, the singularity which was resolved in the static case, is introduced back into the model. However, the slowly-rotating limit of this black hole is singularity-free. Furthermore, we show that the presence of quantum parameters modifies the location of the horizons, temperature, and entropy of the black hole, and allows the existence of naked singularities even if the ratio of the spin parameter to mass of the black hole is less than unity. Finally, by computing the shadow parameters of this black hole and comparing them with data from the Event Horizon Telescope for both M87* and Sgr A*, we set bounds on one of the quantum parameters of the model, and show that there is a limit on the angular momentum of M87* if this model is valid.