Electromagnetic fields associated with a charged black hole extend outside the event horizon, as established by standard charged black hole metrics and near-horizon particle dynamics.
The claim states that electromagnetic fields escape (or are present outside) the event horizon of a charged black hole. In general relativity, a charged black hole is described by the Reissner-Nordström metric (or extensions), which features an electrostatic/electromagnetic field extending through the spacetime outside the event horizon. The retrieved papers discuss charged black holes, quantum corrections to Reissner-Nordström spacetimes, and charged particle dynamics near the event horizon, all of which presuppose and study external electromagnetic fields. Therefore, the claim is supported.