Documentation

LeanPool.Superdiffusion.Algsuperdiff.Section4.Provider.Regularity.RootAssemblyChain

RootAssemblyChain #

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

t.regularity root assembly, part two: the carrier bridge and the bracket #

The gap this module closes #

The frozen root, by contrast, states e.energy.density.estimate in ℝ≥0∞:

  ENNReal.ofReal (√ν) * eLpNorm (fun y => √(vecNormSq (u.grad y))) 2
      (normalizedVolumeMeasureOn ((x+□_n) ∩ □_m))
    ≤ ENNReal.ofReal (C·3^{(1-α)(m-n)}) *
        (ENNReal.ofReal (√ν) * eLpNorm … (normalizedVolumeMeasureOn □_m)
          + ENNReal.ofReal (√σ_m⁻¹·3^{m/2}·K_g)
          + ENNReal.ofReal (√σ_m·3^{m/2}·K_h)) .

Two things separate the two ends, and N is an estimate:

  1. The carrier. Support.normalizedL2On W f is the toReal of eLpNorm f 2 (normalizedVolumeMeasureOn W) (the proved dictionary Support.normalizedL2On_eq_toReal_eLpNorm_normalizedVolumeMeasureOn), so a real inequality lifts to the ℝ≥0∞ one exactly when the eLpNorm is finite. §1 proves the finiteness from the H¹ datum the root's own binders carry and §2 performs the lift into the root's three-leg and two-leg bracket shapes.

  2. The bracket. The chain's output carries two powers of three (3^{(1-α)(m-n)} on the oscillation half and 3^{(3/4)(1-α)(m-n)} on the data half) and its own data scalars dataG, dataM; the root prints ONE power and the two seminorm legs √σ_m⁻¹·3^{m/2}K_g, √σ_m·3^{m/2}K_h. §3 collapses the former into the latter. The collapse is pure arithmetic: 3^{3E/4} ≤ 3^E at E ≥ 0 and two DOMINATION hypotheses (dataG and dataM are K_g-legs), each of which is a proved conversion, not a new estimate.

§4 composes §2 and §3 with energyDensityEstimate_offGrid_pair and produces the frozen root's two-clause conclusion at an arbitrary centre x ∈ □_m.

References #

1. Finiteness of the normalized L² norm #

The bridge. On a window of nonzero finite volume carrying an L² datum, the frozen root's ℝ≥0∞ quantity is the ENNReal.ofReal of the proved chain's real quantity.

2. The lift of a real display into the root's bracket #

The three-leg lift. A real e.energy.density.estimate display becomes the frozen root's ℝ≥0∞ display, with the bracket in the root's own shape (the √ν-weighted □_m leg plus two ENNReal.ofReal data legs).

3. The bracket collapse #

3^{(3/4)E} ≤ 3^E at E ≥ 0.

4. Volume data of the two windows #

The lattice window of the off-grid transfer has nonzero volume.

The lattice window of the off-grid transfer has finite volume.

4b. The L² datum of the displayed function #

The displayed function is L². The frozen root's left-hand side is the L² norm of |∇u|, and its L² membership is a of the root's own u: H1Function □_m — not an extra hypothesis.

5. The frozen root's two-clause conclusion at an arbitrary centre #

theorem Algsuperdiff.Section4.Provider.Regularity.rootEnergyDensityPair_of_realDisplays {d : ℕ} (nu : ℝ) (f : HCPolySupport.Vec d → ℝ) {x : HCPolySupport.Vec d} {m n : ℤ} {C alpha A B : ℝ} (hx : x ∈ HCPolySupport.openCubeSet (HCPolySupport.originCube d m)) (hnm : n ≤ m) (hC : 0 ≤ C) (hfM : MeasureTheory.MemLp f 2 (MeasureTheory.volume.restrict (HCPolySupport.openCubeSet (HCPolySupport.originCube d m)))) (hzfull : √nu * Support.normalizedL2On (ExcessDecay.truncatedWindow (offGridCentre n x) m (n + 1)) f ≤ C * Real.rpow 3 ((1 - alpha) * (↑m - ↑n)) * (√nu * Support.normalizedL2On (HCPolySupport.openCubeSet (HCPolySupport.originCube d m)) f + A + B)) (hzinner : offGridCentre n x ∈ HCPolySupport.openCubeSet (HCPolySupport.originCube d (m - 1)) → √nu * Support.normalizedL2On (ExcessDecay.truncatedWindow (offGridCentre n x) m (n + 1)) f ≤ C * Real.rpow 3 ((1 - alpha) * (↑m - ↑n)) * (√nu * Support.normalizedL2On (HCPolySupport.openCubeSet (HCPolySupport.originCube d m)) f + A)) :

The root assembly's ℝ-to-root step.

From the §4.4 chain's real display at the lattice centre z = offGridCentre n x and scale n+1 — in both the general and the boundary-leg-free form — this produces the frozen root's two-clause conclusion at an arbitrary centre x ∈ □_m and scale n, at the constant 3^d·C (the off-grid transfer factor and nothing else).

The only data beyond the root's own binders is hfM, the L² membership of the displayed function on □_m — a field of the root's u : H1Function □_m, not a new hypothesis.