Documentation

LeanPool.Superdiffusion.Algsuperdiff.Section3.Provider.BadEvents.BadEventLemmaUmbrella

BadEventLemmaUmbrella #

Ported from scottnarmstrong/Superdiffusion at 7f20476385d4af418f110303085ad0740c9eba46. Module imports, support namespace and local option directives adapted for Lean Pool.

The umbrella of l.bad.event.lemma, re-assembled through both ellipticity branches #

BadEventLemmaFull.measureReal_compl_goodLocalEvent_le_full_of_coarseBounds assembles ABK26's e.bad.event.Q.estimate over the full range of m, n, but it routes both branches of the coarse-ellipticity half through BadEventLemmaCases.measureReal_coarseEllipticityFailure_le_of_coarseBounds, which is the branch n ≥ m. On the other branch that is a degeneracy, not a generalization:

n < m = Q.scale   ⟹   scaleGapPos Q.scale n = 0
                  ⟹   3^{(1/4) scaleGapPos Q.scale n} = 1 ,

The umbrella is therefore vacuous on n < m. The collapse itself is machine-checked here (three_rpow_scaleGapPos_eq_one_of_lt), so the diagnosis is not commentary.

This module supplies the missing import edge and re-assembles the umbrella so that each branch is served by its own conditional Provider A.

The shape of the re-assembly, and why the constant is re-based #

EllipticityBranchLow delivers its branch at the re-based constant 2 Ccg (the gap constant G(1/8,1/16,2) ≤ 2 of the transfer), i.e. it bounds coarseEllipticityFailure M (2 Ccg) Q n. The umbrella below is therefore stated at the good local event Q(m,n,z) read at 2 Ccg, on both branches. On n ≥ m the re-basing costs nothing beyond monotonicity of the failure event in the constant (coarseEllipticityFailure_two_mul_subset, proved here), so the proved n ≥ m branch is consumed at its own constant Ccg and its own binder shape, verbatim.

The two branches deliver different double exponents --- Ccg^{-1}/4 on n ≥ m, Ccg^{-1}/8 on n < m (the gate's own budget) --- and the umbrella is stated at the weaker of the two, Ccg^{-1}/8, exactly as EllipticityBranchLow's header predicts. The n ≥ m branch alone remains available at Ccg^{-1}/4 from BadEventLemmaCases; nothing is lost, and nothing here re-derives either tail.

The four disclosed conditional binders (no graph status) #

Each is guarded by the branch that needs it, which is the whole content of the re-assembly:

hrestrict is the restriction, already guarded by n < Q.scale in BadEventLemmaFull, forwarded unchanged.

The 1 ≤ Ccg normalization, named precisely #

Both branches need 1 ≤ Ccg, and the frozen coarse_ellipticity_bounds supplies only a positive constant. The binding constraint is the low branch: its per-translate tail is read at the level Ccg / exp(-Ccg^{-1}E^{-2}gamma^{-1}), which must be ≥ 1 for the weak-Orlicz tail to apply, and that is exactly 1 ≤ Ccg (EllipticityBranchLow.measureReal_translateCoarseEllipticityTail_le). The high branch needs only 1 ≤ 2 Ccg. So the re-assembly inherits 1 ≤ Ccg unchanged from the two proved branches and adds nothing; it is discharged only after the frozen theorem is proved with its own choice of constant, exactly as BadEventLemmaCases.lean records. No step here is blocked by the gap, and no step here weakens it.

For the record, the gap looks closable in one lemma, which is not built here (it belongs in Section3/Probability/LowerFamily.lean, not in a bad-event umbrella, and it changes how the frozen conclusion is consumed): re-basing the frozen constant to max 1 Ccg needs IsLowerIntegerFamilyOrlicz monotone upward in the deterministic profile b (immediate from its dominates clause, X L ω ≤ b + Y ω) and in the Orlicz scale A (CoarseGraining's proved IndependentSums.IsBigOWith.mono_scale), together with monotonicity of lowerEllipticityProfile Ccg gamma s 2 = Ccg s (2s-gamma)^{-1} in Ccg. Until that lemma exists, 1 ≤ Ccg stays a binder here, as it already is upstream.

What is not proved #

Main results #

References #

Monotonicity of the failure event in its constant #

The coarse-ellipticity failure event is antitone in the constant: raising the threshold shrinks the event. This is what lets the proved n ≥ m branch, proved at Ccg, be read at the re-based constant 2 Ccg.

The branch n ≥ m, at the re-based constant and the reconciled exponent #

The case n ≥ m of the coarse-ellipticity branch, read at the re-based constant 2 Ccg and at the exponent Ccg^{-1}/8 at which the two branches meet:

P[ lambda^{-1}_{1/8,2}(z+square_m; a_n) sigmabar_{n-1} > 2 . 3^{(1/4)(n-m)_+} (2 Ccg) ]
  <= exp( - exp( (1/8) Ccg^{-1} E^{-2} gamma^{-1} ) ) .

Both weakenings are theorems: the event shrinks when the constant is doubled (coarseEllipticityFailure_two_mul_subset), and exp((1/8)X) ≤ exp((1/4)X) for X ≥ 0. The binders are those of BadEventLemmaCases.measureReal_coarseEllipticityFailure_le_of_coarseBounds, verbatim and at the un-re-based Ccg.

The umbrella over the full range, each branch on its own conditional A #

theorem Algsuperdiff.Section3.Provider.BadEvents.measureReal_compl_goodLocalEvent_le_full_reassembled {d : ℕ} (M : ABKModel d) {Ccg : ℝ} (hCcg : 1 ≤ Ccg) (Q : HCPolySupport.TriadicCube d) {n m0 : ℤ} {E : { E : ℝ // 1 ≤ E }} (hS : Frozen.Section3.inductionState M (m0 - 1) E) (hn : n ≤ m0 - 1) (hadm : badEventOscLowAdmissibleConst d (2 * Ccg) ≤ ↑E * Disorder.cstar M) (hgammaE : M.gamma ≤ ↑E ^ (-5)) (hrestrict : n < Q.scale → 1 ≤ badEventOscFullRate M (2 * Ccg) Q n) (hmono : Q.scale ≤ n → ∀ (omega : Cutoff.CutoffSample d), cubeLowerEllipticityInv M Q n (1 / 8) measureReal_coarseEllipticityFailure_two_mul_le_of_coarseBounds._proof_1 exponentTwo omega ≤ 3 ^ (1 / 4 * scaleGapPos Q.scale n) * Observable.cutoffLowerEllipticityInv M n n (1 / 8) measureReal_coarseEllipticityFailure_two_mul_le_of_coarseBounds._proof_1 exponentTwo omega) (hcgHigh : Q.scale ≤ n → Probability.IsLowerIntegerFamilyOrlicz (↑(Cutoff.cutoffSampleLaw M)) (HCPolySupport.IndependentSums.gammaSigma ((1 - 1 / 2) / 2)) (fun (L : ℤ) (omega : Cutoff.CutoffSample d) => Observable.cutoffLowerEllipticityInv M n L (1 / 8) measureReal_coarseEllipticityFailure_two_mul_le_of_coarseBounds._proof_1 exponentTwo omega * ↑(Annealed.sigmaBar M (n - 1))) (n - 1) (lowerEllipticityProfile Ccg M.gamma (1 / 8) exponentTwo) (Real.exp (-(Ccg⁻¹ * (↑E)⁻¹ ^ 2 * M.gamma⁻¹)))) (hcgLow : n < Q.scale → ∀ R ∈ HCPolySupport.descendantsAtScale Q n, Probability.IsLowerIntegerFamilyOrlicz (↑(Cutoff.cutoffSampleLaw M)) (HCPolySupport.IndependentSums.gammaSigma ((1 - 1 / 2) / 2)) (fun (L : ℤ) (omega : Cutoff.CutoffSample d) => cubeLowerEllipticityInv M R L (1 / 16) measureReal_compl_goodLocalEvent_le_full_reassembled._proof_1 exponentTwo omega * ↑(Annealed.sigmaBar M (n - 1))) (n - 1) (lowerEllipticityProfile Ccg M.gamma (1 / 16) exponentTwo) (Real.exp (-(Ccg⁻¹ * (↑E)⁻¹ ^ 2 * M.gamma⁻¹)))) (hgap : n < Q.scale → ↑d * (↑Q.scale - ↑n) * Real.log 3 + Real.exp (1 / 8 * (Ccg⁻¹ * (↑E)⁻¹ ^ 2 * M.gamma⁻¹)) ≤ Real.exp (1 / 4 * (Ccg⁻¹ * (↑E)⁻¹ ^ 2 * M.gamma⁻¹))) :
(↑(Cutoff.cutoffSampleLaw M)).real (goodLocalEvent M (2 * Ccg) Q n)ᶜ ≤ Real.exp (-badEventOscFullRate M (2 * Ccg) Q n) + Real.exp (-Real.exp (1 / 8 * (Ccg⁻¹ * (↑E)⁻¹ ^ 2 * M.gamma⁻¹)))

l.bad.event.lemma over the full range of m, n, re-assembled (ABK26, e.bad.event.Q.estimate), at the re-based constant 2 Ccg:

P[ not Q(m,n,z) ]
  <= exp( - c c_star gamma^{-1} 3^{-5(m-n)_+} 3^{(n-m)_+} )
     + exp( - exp( (1/8) Ccg^{-1} E^{-2} gamma^{-1} ) ) ,

with c = badEventOscLowConst d (2 Ccg), dimension-only.

Unlike BadEventLemmaFull.measureReal_compl_goodLocalEvent_le_full_of_coarseBounds, the coarse-ellipticity half is served on n < Q.scale by EllipticityBranchLow.measureReal_coarseEllipticityFailure_le_printed_of_gap rather than by the n ≥ m branch, whose hmono binder degenerates there to a refuted statement (three_rpow_scaleGapPos_eq_one_of_lt). Accordingly hmono and the centered hcg are hypothesised only under Q.scale ≤ n, and the translate hcg and the entropy gate only under n < Q.scale.

The two hcg binders have the shape of specializations of the proved p.cg.ellipticity.bounds, but this statement does not itself perform their translated-carrier discharge; hgap and hrestrict restrict the two branches.