Loopy black-hole remnants

The quantized area predicted by loop quantum gravity suggests the existence of a lower bound for black-hole horizons. We prove this intuition within a covariant effective model for spherical loop quantum gravity, where nonsingular quasi-static black holes evaporate until their horizons attain the smallest positive eigenvalue of the area operator. Consistent with the third law of black-hole thermodynamics, this final state—characterized by vanishing temperature and entropy — cannot be realized in finite time. The process thus leads to the formation of stable remnants, whose estimated masses are approximately 20.94 [Formula: see text]g, lying in the Planck regime.