fpvandoorn/carleson
Source indexedtheorem · leanprover/lean4:v4.32.0
MeasureTheory.exists_hasStrongType_real_interpolation
Carleson.ToMathlib.RealInterpolation.Main · Carleson/ToMathlib/RealInterpolation/Main.lean:1436 to 1454
Source documentation
Marcinkiewicz real interpolation theorem
Exact Lean statement
theorem exists_hasStrongType_real_interpolation {p₀ p₁ q₀ q₁ p q : ℝ≥0∞}
[TopologicalSpace E₁] [ESeminormedAddMonoid E₁]
[TopologicalSpace E₂] [ContinuousENorm E₂]
(hp₀ : p₀ ∈ Ioc 0 q₀) (hp₁ : p₁ ∈ Ioc 0 q₁) (hq₀q₁ : q₀ ≠ q₁)
{C₀ C₁ A : ℝ≥0} (hA : 1 ≤ A) (ht : t ∈ Ioo 0 1) (hC₀ : 0 < C₀) (hC₁ : 0 < C₁)
(hp : p⁻¹ = (1 - t) / p₀ + t / p₁) (hq : q⁻¹ = (1 - t) / q₀ + t / q₁)
(hmT : ∀ f, MemLp f p μ → AEStronglyMeasurable (T f) ν)
(hT : AESubadditiveOn T (fun f ↦ MemLp f p₀ μ ∨ MemLp f p₁ μ) A ν)
(h₀T : HasWeakType T p₀ q₀ μ ν C₀) (h₁T : HasWeakType T p₁ q₁ μ ν C₁) :
HasStrongType T p q μ ν (C_realInterpolation p₀ p₁ q₀ q₁ q C₀ C₁ A t)Complete declaration
Lean source
Full Lean sourceLean 4
theorem exists_hasStrongType_real_interpolation {p₀ p₁ q₀ q₁ p q : ℝ≥0∞} [TopologicalSpace E₁] [ESeminormedAddMonoid E₁] [TopologicalSpace E₂] [ContinuousENorm E₂] (hp₀ : p₀ ∈ Ioc 0 q₀) (hp₁ : p₁ ∈ Ioc 0 q₁) (hq₀q₁ : q₀ ≠ q₁) {C₀ C₁ A : ℝ≥0} (hA : 1 ≤ A) (ht : t ∈ Ioo 0 1) (hC₀ : 0 < C₀) (hC₁ : 0 < C₁) (hp : p⁻¹ = (1 - t) / p₀ + t / p₁) (hq : q⁻¹ = (1 - t) / q₀ + t / q₁) (hmT : ∀ f, MemLp f p μ → AEStronglyMeasurable (T f) ν) (hT : AESubadditiveOn T (fun f ↦ MemLp f p₀ μ ∨ MemLp f p₁ μ) A ν) (h₀T : HasWeakType T p₀ q₀ μ ν C₀) (h₁T : HasWeakType T p₁ q₁ μ ν C₁) : HasStrongType T p q μ ν (C_realInterpolation p₀ p₁ q₀ q₁ q C₀ C₁ A t) := by intro f hf refine ⟨hmT f hf, ?_⟩ have hp' : p⁻¹ = (1 - t) * p₀⁻¹ + t * p₁⁻¹ := by rw [hp]; congr have hq' : q⁻¹ = (1 - t) * q₀⁻¹ + t * q₁⁻¹ := by rw [hq]; congr have obs : SubadditiveTrunc T A f ν := Subadditive_trunc_from_SubadditiveOn_Lp₀p₁ hp₀.1 hp₁.1 hA ht hp' hT hf rw [coe_C_realInterpolation hp₀ hp₁ hq₀q₁] <;> try assumption have : 0 < A := lt_of_lt_of_le (by norm_num) hA apply exists_hasStrongType_real_interpolation_aux₄ <;> assumption