Hawking Radiation & the Information Problem: Physical Mechanisms

The Hawking temperature is inversely proportional to black-hole mass, so stellar and supermassive black holes are extraordinarily cold. Evaporation becomes significant only over immense timescales. The information problem asks how the detailed quantum state of infalling matter can be reconciled with apparently thermal outgoing radiation and eventual disappearance of the hole.

The modern derivation treats quantum fields on curved spacetime; particle definitions for observers before and after gravitational collapse do not coincide, leading distant observers to detect thermal radiation. The popular picture of particle-antiparticle pairs appearing exactly at the horizon is only a heuristic and should not be mistaken for the full calculation.

Hawking radiation has not been directly detected from astrophysical black holes because their predicted temperatures are far below surrounding backgrounds. The theory is strongly grounded in quantum field theory in curved spacetime, while the information question remains an active theoretical research problem.

The full derivation uses quantum fields in curved spacetime, not a literal picture of particle pairs popping into existence exactly at the horizon. Different definitions of vacuum before and after collapse lead distant observers to detect thermal radiation.