Do higher-order quantum corrections reshape charged black holes?

When higher-derivative terms mixing gravity and electromagnetism are added to Einstein's equations, charged (Reissner-Nordström) black holes get modified in calculable ways. Solving the corrected field equations exactly, the authors find that the extremal black hole has non-negative temperature only when the weak gravity conjecture holds — a speculative but widely-discussed constraint on any consistent quantum gravity theory. This neatly rules out one specific candidate theory, Drummond-Hathrell, and ties abstract conjectures to concrete black hole thermodynamics.