Documentation

LeanPool.Superdiffusion.Algsuperdiff.Section3.Provider.Affine.GlobalCompetitor

GlobalCompetitor #

Ported from scottnarmstrong/Superdiffusion at 7f20476385d4af418f110303085ad0740c9eba46. Module imports, support namespace and local option directives adapted for Lean Pool.

The global piecewise-affine competitor ℓ̂_p on □_m #

The engine: the closed-star lemma #

The correction is a geometric one, and it is mem_commonCoarseMesh_of_vertex_mem_closedCubeCarrier:

if a vertex of a scale-s root cell lies in the closed carrier of C, then that cell already belongs to the window mesh commonCoarseMesh 𝒩(C) s.

Equivalently: a root cell outside the window mesh has all its vertices off the closed bad cubes, so its interpolant of the global datum is exactly ℓ_p (eqOn_vertexSet_competitorVertexData_linearFn_of_notMem_commonCoarseMesh). Its proof is the locally-finite closed-star argument:

  1. exists_whitneyCube_inter_cubeSet_mem_closedBall -- an interior point v in the closed realization of a triadic cube B lies in the closed cube of some Whitney cube whose half-open cube already meets B. This is local finiteness of 𝒲(□_m) in the interior, obtained from the upper half (boundaryMargin_le_of_mem_whitneyLayer): a point at boundary margin ≥ ε can only be met by Whitney cubes of boundedly many layers, and each layer is a Finset.
  2. that Whitney cube touches C (both closed cubes contain v), hence lies in 𝒩(C), hence has scale ≥ s by the two-layer window hypothesis;
  3. a scale-s root cube meeting a Whitney cube of scale ≥ s is a descendant of it (mem_descendantsAtScale_of_cubeSet_inter_nonempty), so B sits in a window cube and the cell is a window cell.

No "extra collar layer" and no cutoff is needed; the mesh is the same single-scale mesh, extended over the root cube.

Scope: what this module does NOT do #

References #

Local finiteness of the Whitney partition in the interior #

The closed-star bridge. An interior point in the closed realization of a triadic cube B is in the closed realization of some Whitney cube whose half-open realization already meets B.

A scale-s triadic cube of the root that meets a Whitney cube of scale at least s is a descendant of it.

The closed-star lemma #

The closed-star lemma. If a vertex of a scale-s cell of the root mesh lies in the closed carrier of a family C of Whitney cubes, then the cell already belongs to the common coarse mesh of any window N containing every Whitney cube touching C, provided the window sits at scale at least s.

The root mesh #

A triadic descendant of a Whitney cube is a triadic descendant of the root cube at the same scale.

The global competitor of one bad component #

The global piecewise-affine competitor ℓ̂_p of the bad family C.

Equations
  • One or more equations did not get rendered due to their size.
Instances For

    The global piecewise-constant gradient field ∇ℓ̂_p.

    Equations
    • One or more equations did not get rendered due to their size.
    Instances For

      The matching with ℓ_p off the window #

      The closed-star consequence: on a root cell outside the window mesh the global vertex datum is ℓ_p at every vertex.

      theorem Algsuperdiff.Section3.Provider.Affine.globalCompetitor_eqOn_linearFn_closedCarrier_of_notMem_commonCoarseMesh {d : ℕ} [NeZero d] {m : ℤ} {hn : ℕ → ℕ} {s : ℤ} (hsm : s ≤ m) {C : Set (HCPolySupport.TriadicCube d)} (hC : C ⊆ Whitney.whitneyPartition m hn) {N : Finset (HCPolySupport.TriadicCube d)} (hN : ∀ Q ∈ Whitney.whitneyPartition m hn, (∃ R ∈ C, Whitney.CubeTouch Q R) → Q ∈ N) (hs : ∀ Q ∈ N, s ≤ Q.scale) (p : HCPolySupport.Vec d) {T : Whitney.KuhnCell d} (hT : T ∈ rootCoarseMesh m s) (hTnot : T ∉ commonCoarseMesh N s) :
      theorem Algsuperdiff.Section3.Provider.Affine.notMem_commonCoarseMesh_of_mem_cubeSet {d : ℕ} {m : ℤ} {hn : ℕ → ℕ} {s : ℤ} {N : Finset (HCPolySupport.TriadicCube d)} (hNsub : ∀ Q ∈ N, Q ∈ Whitney.whitneyPartition m hn) (hs : ∀ Q ∈ N, s ≤ Q.scale) {R : HCPolySupport.TriadicCube d} (hR : R ∈ Whitney.whitneyPartition m hn) (hRnot : R ∉ N) {T : Whitney.KuhnCell d} {x : HCPolySupport.Vec d} (hxR : x ∈ HCPolySupport.cubeSet R) (hxT : x ∈ HCPolySupport.cubeSet T.supportCube) :

      A root cell meeting a Whitney cube outside the window is outside the window mesh.

      Continuity #

      "this extension is well-defined and continuous" for the global competitor, on the whole root cube.

      Subordination to SW(□_m) #

      theorem Algsuperdiff.Section3.Provider.Affine.simplexScale_succ_le (m : ℤ) {hn : ℕ → ℕ} {j : ℕ} (hstep' : hn (j + 1) ≤ hn (j + 2) + 1) :
      theorem Algsuperdiff.Section3.Provider.Affine.simplexScale_le_scale_of_mem_window {d : ℕ} {m : ℤ} {hn : ℕ → ℕ} {j : ℕ} (hstep : ∀ (n : ℕ), hn n ≤ hn (n + 1) + 1) {N : Finset (HCPolySupport.TriadicCube d)} (hNsub : ∀ Q ∈ N, Q ∈ Whitney.whitneyPartition m hn) (hNlayer : ∀ Q ∈ N, ∀ (n : ℕ), Q ∈ Whitney.whitneyLayer m hn n → n = j ∨ n = j + 1) (Q : HCPolySupport.TriadicCube d) :

      The window sits at scale at least the common coarse scale.

      theorem Algsuperdiff.Section3.Provider.Affine.exists_rootCell_openCarrier_subset {d : ℕ} {m : ℤ} {hn : ℕ → ℕ} {j n : ℕ} (hstep : ∀ (k : ℕ), hn k ≤ hn (k + 1) + 1) (hns : Whitney.simplexScale m hn n ≤ Whitney.simplexScale m hn j) {Q : HCPolySupport.TriadicCube d} (hQ : Q ∈ Whitney.whitneyLayer m hn n) {T : Whitney.KuhnCell d} (hT : T ∈ Whitney.whitneySimplexCells m hn n Q) :

      The subordination step: a final e.SW.def cell whose simplex scale is not coarser than the common scale sits inside a single root cell.

      The sum_of_a_decomp binder shapes #

      The cell constant of ∇ℓ̂_p on a cell of SW(□_m).

      Equations
      • One or more equations did not get rendered due to their size.
      Instances For
        theorem Algsuperdiff.Section3.Provider.Affine.globalCompetitorSlope_eq_cellSlope {d : ℕ} [NeZero d] {m : ℤ} {hn : ℕ → ℕ} {j : ℕ} (hstep : ∀ (k : ℕ), hn k ≤ hn (k + 1) + 1) (hstep' : hn (j + 1) ≤ hn (j + 2) + 1) {C : Set (HCPolySupport.TriadicCube d)} (hC : C ⊆ Whitney.whitneyPartition m hn) {N : Finset (HCPolySupport.TriadicCube d)} (hNmem : ∀ (Q : HCPolySupport.TriadicCube d), Q ∈ N ↔ Q ∈ Whitney.whitneyNeighborhood m hn C) (hNlayer : ∀ Q ∈ N, ∀ (n : ℕ), Q ∈ Whitney.whitneyLayer m hn n → n = j ∨ n = j + 1) (p : HCPolySupport.Vec d) {T : Whitney.KuhnCell d} (hT : T ∈ Whitney.simplexPartition m hn) :

        The three sum_of_a_decomp clauses at one cell of SW(□_m). The gradient field of the global competitor is constant on the open cell (hFc/hGc), the constant is 0 when the cell's Whitney cube is bad (clause 1) and it is p when the cell's Whitney cube lies off the neighborhood 𝒩(C) (clause 3).