OAI/Geometry/RCD/Heat/HeatPoissonAverage.lean

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4 declarations, 0 contain sorry, 0 declared as axioms

Time variation of averages for a weak Poisson solution

  1. theorem OAI.RegularPointCoordinates.lp_setAverage_eq_inner line 19

    Source documentation

    A finite-set average is a continuous linear functional on L².

    theorem lp_setAverage_eq_inner (A : Set X) (hA : MeasurableSet A) (hAt : μ A ≠ ∞)
        (f : Lp ℝ 2 μ) :
        (⨍ x in A, f x ∂μ) =
          (μ.real A)⁻¹ * inner ℝ (indicatorConstLp 2 hA hAt (1:ℝ)) f := by
    …
  2. theorem OAI.RegularPointCoordinates.heat_setAverage_continuous line 25
  3. theorem OAI.RegularPointCoordinates.heat_setAverage_add line 30
  4. theorem OAI.RegularPointCoordinates.heat_weakLaplacian_average_hasDerivAt line 38

    Source documentation

    The weak Laplacian gives the genuine derivative of every finite-set average, including for initial data with no chosen pointwise representative.

    theorem heat_weakLaplacian_average_hasDerivAt
        (u : SobolevSpace μ hQ) (d : Lp ℝ 2 μ) (hd : IsWeakLaplacian μ hQ u d)
        (A : Set X) (hA : MeasurableSet A) (hAt : μ A ≠ ∞) {t : ℝ} (ht : 0 < t) :
        HasDerivAt (fun s => ⨍ x in A, heatAt μ hQ s (SobolevSpace.toLp μ hQ u) x ∂μ)
          (⨍ x in A, heatAt μ hQ t d x ∂μ) t := by
    …

    Mentions: OAI.RegularPointCoordinates.SobolevSpace, OAI.RegularPointCoordinates.IsWeakLaplacian, OAI.RegularPointCoordinates.heatAt, OAI.RegularPointCoordinates.SobolevSpace.toLp