🌌 ◆ Frontier — not yet benchmarked Ch.11 Physics & Cosmology

Black-Hole Information

Black-Hole Information — Page Curve & Unitarity · Quantum Gravity

Show that black holes preserve information — recover the unitary Page curve of Hawking radiation via the island formula.

📋 The problem

Hawking's calculation implies black holes destroy information, contradicting quantum unitarity. The island / replica-wormhole prescription recovers a unitary 'Page curve' for radiation entropy. Reproducing it tests whether information survives.

🧗 Why it's a grand challenge

It requires fine-grained entanglement entropy with quantum-extremal-surface (island) contributions; analytic only in toy models; deviations diagnose where semiclassical gravity fails.

🧮 Governing model

S_rad = min ext_I [ Area(∂I)/4G_N + S_bulk(R∪I) ]  (island formula)

Fine-grained entropy of Hawking radiation S_rad(t) with the island/QES prescription; unitarity ⇒ Page curve that rises then falls.

Current best: Islands / replica-wormhole Page-curve derivations

🧭 Possible approaches

  • Quantum-extremal-surface / island solvers for radiation entropy
  • Replica-wormhole emulators
  • Learning the Page transition in toy evaporating models

🎯 Build the benchmark

Recover the unitary Page curve for an evaporating model with low deviation, using the island formula.

Metric: page_dev — deviation from unitary Page curve (lower better)

Datasets to start from: Replica-wormhole entropy benchmark set, Evaporating-model entanglement series

☆ Build the benchmark — earn PWM →

🤖 Build an AI agent to solve it

An agent that, given an evaporation model, computes the entropy curve and locates the Page time and islands.

Once a benchmark exists, an AI4Science agent can iterate solutions against it — every verified solution earns PWM.

⚛ View the machine-readable principle (L1-914) → ← All grand hard problems

This is a frontier framing page — an open problem, not yet benchmarked or verified, unlike PWM's mature computational-imaging benchmarks.