OAI/Analysis/LipschitzHilbert/Estimates/PublishedInputs.lean

GitHub source file

17 declarations, 0 contain sorry, 0 declared as axioms

Published inputs for the Lipschitz-direction Hilbert transform

The two classical estimates used by the manuscript are stated as propositions. Their deterministic consequences make the quantifiers needed for the finite rectangle and martingale applications explicit.

The deterministic consequences below make the quantifiers relevant to the application explicit: a union of high-average rectangles, and a variation sum whose increasing indices may be chosen separately at each point.

  1. abbrev OAI.LipschitzHilbert.Plane line 38

    Also declared: ComparatorChallenges/LipschitzHilbert.lean:15 (same declaration text).

  2. structure OAI.LipschitzHilbert.Rectangle line 41

    Source documentation

    A closed orthogonal rectangle; long and short are full side lengths.

    structure Rectangle where
    …
  3. def OAI.LipschitzHilbert.Rectangle.carrier line 51
  4. theorem OAI.LipschitzHilbert.Rectangle.measurableSet_carrier line 55
  5. def OAI.LipschitzHilbert.Rectangle.popularSet line 63

    Source documentation

    The arc of total angular length short / long about the long-side direction. The field is separately required to have unit norm.

    def popularSet (R : Rectangle) (v : Plane → Plane) : Set Plane :=
    …

    Mentions: OAI.LipschitzHilbert.Rectangle, OAI.LipschitzHilbert.Plane

  6. def OAI.LipschitzHilbert.Rectangle.Admissible line 67

    Source documentation

    Admissibility uses the long-side length restriction, with no restriction when K = 0.

    def Admissible (R : Rectangle) (v : Plane → Plane) (K δ : ℝ≥0) : Prop :=
    …

    Mentions: OAI.LipschitzHilbert.Rectangle, OAI.LipschitzHilbert.Plane

  7. def OAI.LipschitzHilbert.Rectangle.average line 71
  8. def OAI.LipschitzHilbert.rectangleMaximum line 77

    Source documentation

    The finite-rectangle maximal function appearing in the needed specialization.

    def rectangleMaximum {ι : Type*} [Fintype ι] (R : ι → Rectangle)
        (h : Plane → ℝ) (x : Plane) : ℝ≥0∞ :=
    …

    Mentions: OAI.LipschitzHilbert.Rectangle, OAI.LipschitzHilbert.Plane

  9. def OAI.LipschitzHilbert.squareIntegral line 84

    Source documentation

    Squared L² size; using the nonnegative integral also covers intermediate expressions.

    def squareIntegral {Ω : Type*} [MeasurableSpace Ω] (μ : Measure Ω)
        (h : Ω → ℝ) : ℝ≥0∞ := ∫⁻ x, ‖h x‖ₑ ^ 2 ∂μ
  10. def OAI.LipschitzHilbert.LaceyLiInput line 90

    Source documentation

    Lacey--Li, published result 1.10 / equation (1.11), specialized to finite families in squared weak-type form (also arXiv:math/0601213v2, Theorem 1.4). C is the weak L² operator constant before squaring.

    def LaceyLiInput : Prop :=
    …
  11. theorem OAI.LipschitzHilbert.rectangle_union_subset_level line 101

    Source documentation

    If every selected rectangle has a high average, their union lies in the level set.

    theorem rectangle_union_subset_level {ι : Type*} [Fintype ι]
        (R : ι → Rectangle) (h : Plane → ℝ) (t : ℝ≥0)
        (havg : ∀ i, (t : ℝ≥0∞) < (R i).average h) :
        (⋃ i, (R i).carrier) ⊆ {x | (t : ℝ≥0∞) < rectangleMaximum R h x} := by
    …

    Mentions: OAI.LipschitzHilbert.Rectangle, OAI.LipschitzHilbert.Plane, OAI.LipschitzHilbert.rectangleMaximum

  12. theorem OAI.LipschitzHilbert.disjoint_witness_packing line 117

    Source documentation

    Disjoint popularity witnesses turn a covering bound into a weighted packing bound. In the manuscript, w i is a top rectangle's area and a its popularity lower bound.

    theorem disjoint_witness_packing {Ω ι : Type*} [MeasurableSpace Ω] [Fintype ι]
        (μ : Measure Ω) (E R : ι → Set Ω) (w : ι → ℝ≥0∞) (a : ℝ≥0∞)
        (hmeas : ∀ i, MeasurableSet (E i))
        (hdisj : Pairwise fun i j => Disjoint (E i) (E j))
        (hsub : ∀ i, E i ⊆ R i) (hsize : ∀ i, a * w i ≤ μ (E i)) :
        a * ∑ i, w i ≤ μ (⋃ i, R i) := by
    …
  13. theorem OAI.LipschitzHilbert.laceyLi_union_bound line 131

    Source documentation

    The precise covering consequence used for the popular-top count.

    theorem laceyLi_union_bound (hLL : LaceyLiInput) :
        ∃ C : ℝ≥0, 0 < C ∧
          ∀ (v : Plane → Plane) (K δ : ℝ≥0),
            LipschitzWith K v → (∀ x, ‖v x‖ = 1) → 0 < δ → δ < 1 →
            ∀ (n : ℕ) (R : Fin n → Rectangle),
              (∀ i, (R i).Admissible v K δ) →
              ∀ (h : Plane → ℝ), MemLp h 2 volume → ∀ t : ℝ≥0, 0 < t →
                (∀ i, (t : ℝ≥0∞) < (R i).average h) →
                (t : ℝ≥0∞) ^ 2 * volume (⋃ i, (R i).carrier) ≤
                  (C : ℝ≥0∞) ^ 2 / (δ : ℝ≥0∞) * squareIntegral volume h := by
    …

    Mentions: OAI.LipschitzHilbert.LaceyLiInput, OAI.LipschitzHilbert.Plane, OAI.LipschitzHilbert.Rectangle, OAI.LipschitzHilbert.squareIntegral

  14. def OAI.LipschitzHilbert.variationCube line 149

    Source documentation

    Cubed variation of a finite scalar sequence. Repetitions in the monotone list allow every shorter partition to be padded to length N + 1.

    def variationCube {Ω : Type*} (F : ℕ → Ω → ℝ) (N : ℕ) (x : Ω) : ℝ≥0∞ :=
    …
  15. def OAI.LipschitzHilbert.LepingleInput line 159

    Source documentation

    Lépingle's unweighted scalar L² bound for 3-variation. The constant is uniform in the probability space, the filtration, and the finite horizon.

    def LepingleInput : Prop :=
    …
  16. theorem OAI.LipschitzHilbert.selected_variation_le line 169

    Source documentation

    Pointwise-selected increasing partitions are controlled by the full variation.

    theorem selected_variation_le {Ω : Type*} (F : ℕ → Ω → ℝ) (N : ℕ)
        (p : Ω → Fin (N + 1) → Fin (N + 1)) (hp : ∀ x, Monotone (p x)) (x : Ω) :
        (∑ i : Fin N, ‖F (p x i.succ) x - F (p x i.castSucc) x‖ₑ ^ 3) ≤
          variationCube F N x := by
    …

    Mentions: OAI.LipschitzHilbert.variationCube

  17. theorem OAI.LipschitzHilbert.lepingle_selected_bound line 182

    Source documentation

    The published estimate also permits the endpoints to depend on the point. No measurability of the selection is needed for the nonnegative upper integral.

    theorem lepingle_selected_bound (hL : LepingleInput) :
        ∃ C : ℝ≥0, 0 < C ∧
          ∀ (Ω : Type) (m : MeasurableSpace Ω) (μ : Measure Ω),
            IsProbabilityMeasure μ →
            ∀ (ℱ : Filtration ℕ m) (F : ℕ → Ω → ℝ),
              Martingale F ℱ μ → (∀ n, MemLp (F n) 2 μ) → ∀ (N : ℕ)
                (p : Ω → Fin (N + 1) → Fin (N + 1)),
                (∀ x, Monotone (p x)) →
                (∫⁻ x, (∑ i : Fin N,
                  ‖F (p x i.succ) x - F (p x i.castSucc) x‖ₑ ^ 3) ^ (2 / 3 : ℝ) ∂μ) ≤
                  (C : ℝ≥0∞) ^ 2 * squareIntegral μ (F N) := by
    …

    Mentions: OAI.LipschitzHilbert.LepingleInput, OAI.LipschitzHilbert.squareIntegral