OAI/Topology/ArtinGroups/ParabolicIntersections/MeshTrace.lean

GitHub source file

6 declarations, 0 contain sorry, 0 declared as axioms

Positive weighted traces detect vanishing of all endpoint projections.

  1. def OAI.HarmonicArtin.ParabolicIntersections.meshWeightedTrace line 12
  2. lemma OAI.HarmonicArtin.ParabolicIntersections.meshWeightedTrace_nonneg line 16
  3. theorem OAI.HarmonicArtin.ParabolicIntersections.meshWeightedTrace_zero line 27

    Source documentation

    Strict positivity of the vertex weights turns a zero weighted trace of orthogonal projections into the vanishing of each projection.

    theorem meshWeightedTrace_zero {D : V → Type} [∀ v, Fintype (D v)]
        (μ : V → ℝ) (hμ : ∀ v, 0<μ v) (P : ∀ v, Matrix (D v) (D v) ℂ)
        (hstar : ∀ v, (P v).conjTranspose=P v) (hsq : ∀ v, P v*P v=P v)
        (hz : meshWeightedTrace μ P=0) : ∀ v, P v=0 := by
    …

    Mentions: OAI.HarmonicArtin.ParabolicIntersections.meshWeightedTrace

  4. lemma OAI.HarmonicArtin.ParabolicIntersections.meshExtend_trace line 54
  5. def OAI.HarmonicArtin.ParabolicIntersections.meshEdgeFlip line 61

    Source documentation

    Reversal of an oriented edge exchanges the two endpoint sums.

    def meshEdgeFlip : (Σ v : V, {u : V // G.Adj u v}) ≃
        (Σ v : V, {u : V // G.Adj u v}) where
    …
  6. lemma OAI.HarmonicArtin.ParabolicIntersections.meshWeightedTrace_extend line 69

    Source documentation

    Extension multiplies the weighted trace by the Perron eigenvalue.

    lemma meshWeightedTrace_extend (μ : V → ℝ) (δ : ℝ)
        (heigen : ∀ v, (∑ u : {u : V // G.Adj u v}, μ u)=δ*μ v)
        {n : ℕ} (P : ∀ v, Matrix (MeshPaths G n v) (MeshPaths G n v) ℂ) :
        meshWeightedTrace μ (meshExtendMatrix G P)=
          (δ : ℂ)*meshWeightedTrace μ P := by
    …

    Mentions: OAI.HarmonicArtin.ParabolicIntersections.MeshPaths, OAI.HarmonicArtin.ParabolicIntersections.meshWeightedTrace, OAI.HarmonicArtin.ParabolicIntersections.meshExtendMatrix