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Project-declaredLean 4.29.0-rc6 · mathlib@5c8398df5281

Caccioppoli weighted on ball of pos Part Approx

DeGiorgi.caccioppoli_weighted_on_ball_of_posPartApprox

Plain-language statement

Ball-specialized weighted Caccioppoli inequality with the truncation witness constructed from the concrete Chapter 02 positive-part API.

Exact Lean statement

theorem caccioppoli_weighted_on_ball_of_posPartApprox
    {u η : E → ℝ} {x₀ : E} {s Cη k : ℝ}
    (A : EllipticCoeff d (Metric.ball x₀ s))
    (hs : 0 < s)
    (hsub : IsSubsolution A u)
    (hu : MemW1pWitness 2 u (Metric.ball x₀ s))
    (happroxBallShift :
      ∃ ψ : ℕ → E → ℝ,
        (∀ n, ContDiff ℝ 1 (ψ n)) ∧
        (∀ n, HasCompactSupport (ψ n)) ∧
        Tendsto
          (fun n =>
            eLpNorm (fun x => ψ n x - (u x - k)) 2
              (volume.restrict (Metric.ball x₀ s)))
          atTop (nhds 0) ∧
        (∀ i : Fin d,
          Tendsto
            (fun n =>
              eLpNorm
                (fun x =>
                  (fderiv ℝ (ψ n) x) (EuclideanSpace.single i 1) - hu.weakGrad x i)
                2 (volume.restrict (Metric.ball x₀ s)))
            atTop (nhds 0)))
    (hη : ContDiff ℝ (⊤ : ℕ∞) η)
    (hη_nonneg : ∀ x, 0 ≤ η x)
    (hη_bound : ∀ x, |η x| ≤ 1)
    (hCη : 0 ≤ Cη)
    (hη_grad_bound : ∀ x, ‖fderiv ℝ η x‖ ≤ Cη)
    (hη_sub_ball : tsupport η ⊆ Metric.ball x₀ s) :
    ∫ x in Metric.ball x₀ s, η x ^ 2 * ‖(positivePartSub_memW1pWitness_on_ball
        hs hu k happroxBallShift).weakGrad x‖ ^ 2 ∂volume ≤
      4 * ellipticityRatio A *
        ∫ x in Metric.ball x₀ s, ‖fderiv ℝ η x‖ ^ 2 * |positivePartSub u k x| ^ 2 ∂volume

Formal artifact

Lean source

Canonical source
Full Lean sourceLean 4
theorem caccioppoli_weighted_on_ball_of_posPartApprox    {u η : E  } {x₀ : E} {s Cη k : }    (A : EllipticCoeff d (Metric.ball x₀ s))    (hs : 0 < s)    (hsub : IsSubsolution A u)    (hu : MemW1pWitness 2 u (Metric.ball x₀ s))    (happroxBallShift :       ψ :   E  ,        ( n, ContDiff  1 (ψ n))         ( n, HasCompactSupport (ψ n))         Tendsto          (fun n =>            eLpNorm (fun x => ψ n x - (u x - k)) 2              (volume.restrict (Metric.ball x₀ s)))          atTop (nhds 0)         ( i : Fin d,          Tendsto            (fun n =>              eLpNorm                (fun x =>                  (fderiv  (ψ n) x) (EuclideanSpace.single i 1) - hu.weakGrad x i)                2 (volume.restrict (Metric.ball x₀ s)))            atTop (nhds 0)))    (hη : ContDiff  (⊤ : ∞) η)    (hη_nonneg :  x, 0  η x)    (hη_bound :  x, |η x|  1)    (hCη : 0  Cη)    (hη_grad_bound :  x, ‖fderiv  η x‖  Cη)    (hη_sub_ball : tsupport η  Metric.ball x₀ s) :    ∫ x in Metric.ball x₀ s, η x ^ 2 * ‖(positivePartSub_memW1pWitness_on_ball        hs hu k happroxBallShift).weakGrad x‖ ^ 2 ∂volume       4 * ellipticityRatio A *        ∫ x in Metric.ball x₀ s, ‖fderiv  η x‖ ^ 2 * |positivePartSub u k x| ^ 2 ∂volume := by  haveI : IsFiniteMeasure (volume.restrict (Metric.ball x₀ s)) := by    rw [isFiniteMeasure_restrict]    exact measure_ball_lt_top.ne  let hw_trunc : MemW1pWitness 2 (positivePartSub u k) (Metric.ball x₀ s) :=    positivePartSub_memW1pWitness_on_ball hs hu k happroxBallShift  have hη_admissible :      MemW01p 2 (deGiorgiCutoffTestGeneral η u k) (Metric.ball x₀ s) :=    deGiorgiCutoffTest_memW01p_on_ball_of_ballPosPartApprox      hs hu hη hη_bound hCη hη_grad_bound hη_sub_ball k happroxBallShift  change    ∫ x in Metric.ball x₀ s, η x ^ 2 *hw_trunc.weakGrad x‖ ^ 2 ∂volume       4 * ellipticityRatio A *        ∫ x in Metric.ball x₀ s, ‖fderiv  η x‖ ^ 2 * |positivePartSub u k x| ^ 2 ∂volume  exact caccioppoli_weighted_of_subsolution isOpen_ball A hsub hu hw_trunc hη hη_nonneg    (by norm_num) hCη hη_bound hη_grad_bound hη_admissible
Project
DeGiorgi
License
Apache-2.0
Commit
4c1b3077d378
Source
DeGiorgi/DeGiorgiIteration/Energy.lean:667-714

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