OAI/Geometry/SurfaceImmersion/Primitive/LoopDensityParameter.lean

GitHub source file

7 declarations, 0 contain sorry, 0 declared as axioms

Smooth local positive solutions of the three density moment equations.

  1. lemma OAI.ClosedSurfaceR4.LoopDensity.augment_smooth line 12
  2. lemma OAI.ClosedSurfaceR4.LoopDensity.background_smooth line 26
  3. lemma OAI.ClosedSurfaceR4.LoopDensity.column_smooth line 30
  4. lemma OAI.ClosedSurfaceR4.LoopDensity.momentMap_smooth line 36
  5. lemma OAI.ClosedSurfaceR4.LoopDensity.weights_smoothAt line 43
  6. lemma OAI.ClosedSurfaceR4.LoopDensity.weights_smoothOn line 50
  7. theorem OAI.ClosedSurfaceR4.LoopDensity.exists_positive_density_near line 58

    Source documentation

    Positive weights and an invertible three-moment matrix persist locally; this constructs an actual smooth positive density with the exact required mean.

    theorem exists_positive_density_near
        (hp : ContDiff ℝ ∞ (fun z : B × ℝ => p z.1 z.2)) (hc : ContDiff ℝ ∞ c)
        (hψ : ∀ i, ContDiff ℝ ∞ (ψ i)) (hψnonneg : ∀ i t, 0 ≤ ψ i t)
        (hψper : ∀ i, Function.Periodic (ψ i) 1)
        {b₀ : B} {ε : ℝ} (hε : 0 < ε) (hM : (momentMap (p b₀) ψ).IsInvertible)
        (hw : ∀ i, 0 < weights (p b₀) ψ ε (c b₀) i) :
        ∃ U : Set B, IsOpen U ∧ b₀ ∈ U ∧ ∃ ρ : B × ℝ → ℝ,
          ContDiffOn ℝ ∞ ρ (U ×ˢ Set.univ) ∧
          (∀ b ∈ U, ∀ t, 0 < ρ (b, t)) ∧
          (∀ b, Function.Periodic (fun t => ρ (b, t)) 1) ∧
          ∀ b ∈ U, (∫ t in 0..1, ρ (b, t) • augment (p b t)) = augment (c b) := by
    …

    Mentions: OAI.ClosedSurfaceR4.LoopDensity.momentMap, OAI.ClosedSurfaceR4.LoopDensity.weights, OAI.ClosedSurfaceR4.LoopDensity.augment