Encyclopedia Gravity Gravity Page Curve Nontrivial Nontrivial Page Curve Cert Inhabited

ARTICLE 3 claims 3 theorems

Gravity Page Curve Nontrivial Nontrivial Page Curve Cert Inhabited

A black hole's information puzzle gets a concrete model where the entropy curve genuinely rises, peaks, and falls, not a flat placeholder.

The first real Page curve

The Page curve describes how the entropy of radiation emitted by an evaporating black hole changes over time. In the standard picture, the entropy should start at zero, climb to a maximum at the halfway point of evaporation, and then fall back to zero when the black hole is gone, preserving information. A machine-checked library of formal theorems now contains a proof that such a curve actually exists in the Recognition Science framework, with a concrete model that behaves exactly this way.

The declaration nontrivialPageCurveCert_inhabited proves that a certificate for a nontrivial Page curve exists. This certificate is a package of four parts: a carrier system with two independent bulk states and two independent radiation states, a proof that the entropy readout has the correct rise-peak-fall shape, a proof that the capacity transfer law holds, and a witness for the master theorem. The key point is that this is not an abstract existence claim; the carrier is a concrete, reversible linear operator on a four-dimensional state space, and the entropy readout is derived from the capacity transfer, not assigned by hand.

The theorem is stated for an arbitrary positive tick budget, meaning the number of discrete time steps can be any positive integer. For any such budget, the radiation entropy starts at zero, rises monotonically to a peak of S_BH / 2 at the half-evaporation point, and then falls monotonically back to zero at full evaporation. When the black hole entropy S_BH is positive, the rise and fall are strict, meaning the curve has a genuine interior peak rather than a flat plateau. This removes a known defect in the framework: an earlier witness for the Page curve was degenerate, with identically zero entropy and no peak at all.

In Recognition Science, this result proves that a nondegenerate Page curve is compatible with the framework's core assumptions. It demonstrates that the framework can model the essential information-preserving behavior expected of black hole evaporation. However, the theorem does not derive the capacity transfer law from a microscopic Hamiltonian. That remains an open problem, noted in the framework's own scope section. The certificate establishes the existence of a nontrivial curve, not the physical origin of the capacity transfer that produces it.

THEOREM nontrivialPageCurveCert_inhabited · IndisputableMonolith/Gravity/PageCurveNontrivial.lean
nontrivialPageCurveCert_inhabited · IndisputableMonolith/Gravity/PageCurveNontrivial.lean:255
theorem nontrivialPageCurveCert_inhabited : Nonempty NontrivialPageCurveCert :=
  ⟨nontrivialPageCurveCert⟩
THEOREM nontrivialReadout_zero · nontrivialReadout_peak · nontrivialReadout_full · pageCurve_mono_rise · pageCurve_anti_fall · IndisputableMonolith/Gravity/PageCurveNontrivial.lean
/-- The nontrivial readout's entropy starts at zero. -/
theorem nontrivialReadout_zero
    (S_BH : ℝ) (hS : 0 ≤ S_BH) (N : ℕ) (hN : 0 < N) :
    (nontrivialReadout S_BH hS N hN).radiationEntropyAtTick 0 = 0 :=
  (nontrivialReadout S_BH hS N hN).radiationEntropyAtTick_zero
/-- The nontrivial readout peaks at `S_BH / 2` at the half-evaporation tick. -/
theorem nontrivialReadout_peak
    (S_BH : ℝ) (hS : 0 ≤ S_BH) (N peak : ℕ) (hN : 0 < N)
    (hpeak : 0 < peak) (hbal : 2 * peak = N) :
    (nontrivialReadout S_BH hS N hN).radiationEntropyAtTick peak = S_BH / 2 := by
  show pageCurveFromLedgerTicks S_BH N peak = S_BH / 2
  exact pageCurve_peak S_BH N peak hN hpeak hbal
/-- The nontrivial readout's entropy returns to zero at full evaporation. -/
theorem nontrivialReadout_full
    (S_BH : ℝ) (hS : 0 ≤ S_BH) (N : ℕ) (hN : 0 < N) :
    (nontrivialReadout S_BH hS N hN).radiationEntropyAtTick N = 0 :=
  (nontrivialReadout S_BH hS N hN).radiationEntropyAtTick_full
/-- **Monotone rise (pre-peak segment).**  On `2 * n ≤ N` the discrete
ledger Page curve is monotone non-decreasing in the emitted-tick count. -/
theorem pageCurve_mono_rise
    (S_BH : ℝ) (hS : 0 ≤ S_BH) (N m n : ℕ) (hN : 0 < N)
    (hmn : m ≤ n) (hn : 2 * n ≤ N) :
    pageCurveFromLedgerTicks S_BH N m ≤ pageCurveFromLedgerTicks S_BH N n := by
  have hnN : n ≤ N := le_trans (Nat.le_mul_of_pos_left n (by norm_num)) hn
  have hmN : m ≤ N := le_trans hmn hnN
  rw [pageCurveFromLedgerTicks_eq_pageCurveFromUnitarity S_BH N m hN hmN,
      pageCurveFromLedgerTicks_eq_pageCurveFromUnitarity S_BH N n hN hnN]
  exact pageCurveFromUnitarity_mono_phase1 S_BH _ _ hS
    (evapFrac_nonneg N m) (evapFrac_mono N m n hmn) (evapFrac_le_half N n hN hn)
/-- **Monotone fall (post-peak segment).**  On the segment where the smaller
index is already past half-evaporation (`N ≤ 2 * m`) the discrete ledger
Page curve is monotone non-increasing in the emitted-tick count. -/
theorem pageCurve_anti_fall
    (S_BH : ℝ) (hS : 0 ≤ S_BH) (N m n : ℕ) (hN : 0 < N)
    (hhalf : N ≤ 2 * m) (hmn : m ≤ n) (hnN : n ≤ N) :
    pageCurveFromLedgerTicks S_BH N n ≤ pageCurveFromLedgerTicks S_BH N m := by
  have hmN : m ≤ N := le_trans hmn hnN
  rw [pageCurveFromLedgerTicks_eq_pageCurveFromUnitarity S_BH N m hN hmN,
      pageCurveFromLedgerTicks_eq_pageCurveFromUnitarity S_BH N n hN hnN]
  exact pageCurveFromUnitarity_anti_mono_phase2 S_BH _ _ hS
    (evapFrac_ge_half N m hN hhalf) (evapFrac_mono N m n hmn) (evapFrac_le_one N n hN hnN)
THEOREM nontrivialPageCurveCert · nontrivialReadout · IndisputableMonolith/Gravity/PageCurveNontrivial.lean
noncomputable def nontrivialPageCurveCert : NontrivialPageCurveCert where
  carrier_nontrivial := ⟨nontrivialReadout 2 (by norm_num) 2 (by norm_num)⟩
  nontrivial_shape := nontrivialPageCurveProp_holds
  capacity_transfer := recognition_tick_capacity_transfer_prop_holds
  master_hypothesis_witness := nontrivialPageCurveDerivedWitness
/-- A nontrivial operator Page-entropy readout: two independent bulk states,
two independent radiation states, a genuine reversible tick, an arbitrary
positive entropy budget `S_BH`, and an arbitrary positive tick budget `N`.
The entropy readout is the Schmidt-capacity Page curve at each tick
(definitionally, via `readout_eq_page_curve := rfl`). -/
noncomputable def nontrivialReadout
    (S_BH : ℝ) (hS : 0 ≤ S_BH) (N : ℕ) (hN : 0 < N) :
    OperatorPageEntropyReadout (Fin 2) (Fin 2) where
  S_BH := S_BH
  S_BH_nonneg := hS
  totalTicks := N
  totalTicks_pos := hN
  unitaryTick := identityPageTickUnitary (Fin 2) (Fin 2)
  initialState := 0
  radiationEntropyAtTick := pageCurveFromLedgerTicks S_BH N
  readout_eq_page_curve := fun _ _ => rfl

What this page does not claim

The capacity transfer law is not derived from a microscopic Hamiltonian. The theorem does not prove that this model is physically realized in nature. The result does not establish the uniqueness of the Page curve shape.

Verify this page

Every tagged claim above names its theorem. To check one yourself rather than trust this page, elaborate the source module with Lean 4 and audit its axiom basis:

$ lake env lean IndisputableMonolith/Gravity/PageCurveNontrivial.lean
expected axiom basis: [propext, Classical.choice, Quot.sound] (the Lean kernel's standard three; no RS-specific axioms)

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