TH = ℏc³ / (8πGMkB) — thermal radiation from the event horizon
Hawking temperature: TH = ℏc³/(8πGMkB) ≈ 6×10⁻⁸ (M☉/M) K.
Evaporation: M(t) ∝ (tevap − t)1/3, tevap ≈ 5120πG²M³/(ℏc⁴).
CMB temperature TCMB ≈ 2.725 K shown for comparison.
A black hole evaporates when TH > TCMB, i.e., M < Mcrit ≈ 2.2×10²² kg.