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TauCeti.KnotTheory.Khovanov.Complex

The normalized Khovanov complex #

For a planar oriented PD-code, TauCeti.OrientedPDCode.khovanovComplex is a quantum-indexed family of native cochain complexes. A state with B-resolutions S occurs in cochain degree |S| - n₋ and carries the quantum shift |S| + n₊ - 2n₋. The differential retains the cube sign (-1)^(#{b ∈ S | b < a}) on the saddle adding a.

khovanovComplexXIso identifies its terms with the finite biproduct of these quantum pieces. The inclusions and projections characterize the terms, and ι_khovanovComplex_d gives the signed saddle differential. The complex is supported in [-n₋, n₊].

khovanovComplexShiftIso compares this explicit state convention to the native cochain shift of the bracket. Its degree-i component is (-1)^(i * n₋), since native shifts change the differential by (-1)^n₋. Quantum shifts raise degrees: the component at j uses the bracket at j - (n₊ - 2n₋).

References #

The normalized Khovanov complex of a planar oriented diagram. Quantum degree j uses bracket degree j - n₊ + 2n₋, and cochain degree i uses cube height i + n₋. Restriction translates indices while preserving the original signed saddle differential.

Instances For

    The definition of the normalized complex as an index translation of the bracket.

    The normalized term in degree i is the signed cube term of height i + n₋.

    Normalization translates the differential without changing its cube signs.

    Comparison with the native cochain shift of the quantum-shifted bracket. The comparison multiplies cochain degree i by (-1)^(i * n₋).

    Instances For
      @[simp]

      The forward shift comparison carries the degreewise normalization sign.

      @[simp]

      The inverse shift comparison carries the same degreewise sign.

      The normalized cube vertex is precisely the quantum piece shifted by the state's stateQuantumShift.

      noncomputable def TauCeti.OrientedPDCode.khovanovComplexι {n : ℕ} (D : OrientedPDCode n) (hD : D.IsPlanar) (R : Type u) [CommRing R] (j : ℤ) {i : ℤ} (S : { S : Finset (Fin n) // ↑S.card = i + ↑D.negativeCrossingCount }) :

      The inclusion of a state vertex into the normalized cochain term of height i + n₋.

      Instances For

        The inclusion of a state vertex is its inclusion into the signed cube term of height i + n₋, which is the normalized term in degree i.

        noncomputable def TauCeti.OrientedPDCode.khovanovComplexπ {n : ℕ} (D : OrientedPDCode n) (hD : D.IsPlanar) (R : Type u) [CommRing R] (j : ℤ) {i : ℤ} (S : { S : Finset (Fin n) // ↑S.card = i + ↑D.negativeCrossingCount }) :

        The projection of a normalized cochain term onto a state vertex.

        Instances For

          The normalized state projection is the cube projection after the index translation.

          @[simp]

          The state projections followed by their inclusions sum to the identity of a normalized cochain term.

          @[simp]

          Inclusion followed by projection is the identity on a state summand.

          @[simp]

          Inclusion followed by projection is the identity on a state summand.

          @[simp]
          theorem TauCeti.OrientedPDCode.khovanovComplexι_π_of_ne {n : ℕ} (D : OrientedPDCode n) (hD : D.IsPlanar) (R : Type u) [CommRing R] (j : ℤ) {i : ℤ} {S T : { S : Finset (Fin n) // ↑S.card = i + ↑D.negativeCrossingCount }} (h : S ≠ T) :

          Inclusion followed by projection onto a distinct state vanishes.

          @[simp]

          Inclusion followed by projection onto a distinct state vanishes.

          theorem TauCeti.OrientedPDCode.khovanovComplex_hom_ext {n : ℕ} (D : OrientedPDCode n) (hD : D.IsPlanar) (R : Type u) [CommRing R] (j : ℤ) {i : ℤ} {A : ModuleCat R} {f g : (D.khovanovComplex hD R j).X i ⟶ A} (h : ∀ (S : { S : Finset (Fin n) // ↑S.card = i + ↑D.negativeCrossingCount }), CategoryTheory.CategoryStruct.comp (D.khovanovComplexι hD R j S) f = CategoryTheory.CategoryStruct.comp (D.khovanovComplexι hD R j S) g) :
          f = g

          Morphisms out of a normalized term are determined by their state restrictions.

          theorem TauCeti.OrientedPDCode.khovanovComplex_hom_ext' {n : ℕ} (D : OrientedPDCode n) (hD : D.IsPlanar) (R : Type u) [CommRing R] (j : ℤ) {i : ℤ} {A : ModuleCat R} {f g : A ⟶ (D.khovanovComplex hD R j).X i} (h : ∀ (S : { S : Finset (Fin n) // ↑S.card = i + ↑D.negativeCrossingCount }), CategoryTheory.CategoryStruct.comp f (D.khovanovComplexπ hD R j S) = CategoryTheory.CategoryStruct.comp g (D.khovanovComplexπ hD R j S)) :
          f = g

          Morphisms into a normalized term are determined by their state projections.

          noncomputable def TauCeti.OrientedPDCode.khovanovComplexXIso {n : ℕ} (D : OrientedPDCode n) (hD : D.IsPlanar) (R : Type u) [CommRing R] (j i : ℤ) :

          Each normalized term is the finite biproduct of the quantum pieces of its states. The index equation |S| = i + n₋ is equivalent to stateCochainDegree(S) = i.

          Instances For
            @[simp]

            On a state summand, the term comparison is the quantum-piece identification.

            @[simp]

            The inverse term comparison includes a quantum piece as its state summand.

            @[simp]

            Projecting the term comparison onto a quantum piece gives the state projection.

            @[simp]

            The product coordinates of the term comparison are its normalized state projections.

            @[simp]

            The inverse term comparison projects a quantum piece onto its state vertex.

            theorem TauCeti.OrientedPDCode.ι_khovanovComplex_d {n : ℕ} (D : OrientedPDCode n) (hD : D.IsPlanar) (R : Type u) [CommRing R] (j : ℤ) {i : ℤ} (S : { S : Finset (Fin n) // ↑S.card = i + ↑D.negativeCrossingCount }) :
            CategoryTheory.CategoryStruct.comp (D.khovanovComplexι hD R j S) ((D.khovanovComplex hD R j).d i (i + 1)) = ∑ a : ↥(↑S)ᶜ, (-1) ^ {b ∈ ↑S | b < ↑a}.card • CategoryTheory.CategoryStruct.comp ((D.resolutionCube hD R (j - ↑D.positiveCrossingCount + 2 * ↑D.negativeCrossingCount)).map (CategoryTheory.homOfLE ⋯)) (D.khovanovComplexι hD R j ⟨insert ↑a ↑S, ⋯⟩)

            The normalized differential on a state is the sum of the saddle edges with the original cube signs. Each cube edge is identified with its actual saddle by PDCode.resolutionCube_map_homOfLE_insert_comp_resolutionCubeι.

            The normalized differential on a state is the sum of the saddle edges with the original cube signs. Each cube edge is identified with its actual saddle by PDCode.resolutionCube_map_homOfLE_insert_comp_resolutionCubeι.

            No cochain terms occur below -n₋.

            No cochain terms occur above n₊.

            The normalized chain groups vanish outside the cochain interval [-n₋, n₊].

            The normalized chain groups vanish outside the translated extreme-resolution quantum interval. Circle counts include all crossing-free components.

            The normalized chain groups are supported in a finite rectangle in the two gradings jointly.