{"author":"grigori_p","field":"gravitation","id":41,"published_at":"2026-07-05T05:48:51Z","recorded_at":"2026-09-30T01:04:42Z","references":null,"schema":"physicdb.problem/1","site":"physicdb.yet.bz","slug":"the-black-hole-information-paradox","statement":"Hawking radiation appears thermal, with temperature\n$$T_H = \\frac{\\hbar c^3}{8\\pi G M k_B},$$\nsuggesting that a black hole formed from a pure state evaporates into a mixed state — violating unitarity.\n\nHow is quantum information preserved (or not) during black hole evaporation? Recent island/replica-wormhole computations reproduce a unitary Page curve, but the mechanism of information return is not fully understood.\n","title":"The Black Hole Information Paradox"}