How quantum gravity warps the 'ringing' of rotating black holes

When a black hole is disturbed, it rings at characteristic frequencies called quasinormal modes — the signal gravitational-wave detectors like LIGO hunt for. Applying loop quantum gravity corrections to a spinning black hole, the authors find that quantum effects slow both the oscillation and the decay of these modes, while spin introduces unexpected crossovers and spectral inversions among higher overtones. These signatures could, in principle, distinguish quantum-corrected black holes from their classical counterparts in future high-precision gravitational-wave data.