OAI/AlgebraicGeometry/PlaneCurves/HomogeneousOrder.lean

GitHub source file

8 declarations, 0 contain sorry, 0 declared as axioms

Homogeneous multiplicity in normal frames and swapped charts; Homogeneous smooth curve charts

  1. def OAI.Nagata.Workers.W28.normalizedCurvePoint line 17

    Source documentation

    Actual affine chart coordinates of a homogeneous analytic parametrization.

    def normalizedCurvePoint (X : Fin 3 → ℂ → ℂ) (c : Fin 3) (z : ℂ) : ComplexPlane :=
    …

    Mentions: OAI.Nagata.Workers.W28.ComplexPlane

  2. theorem OAI.Nagata.Workers.W28.normalizedCurvePoint_analyticAt line 20
  3. theorem OAI.Nagata.Workers.W28.normalizedCurvePoint_equation line 28

    Source documentation

    The actual homogeneous curve equation implies the actual affine chart equation.

    theorem normalizedCurvePoint_equation
        (G : MvPolynomial (Fin 3) ℂ) (k : ℕ) (hG : G.IsHomogeneous k)
        (X : Fin 3 → ℂ → ℂ) (c : Fin 3) (z : ℂ)
        (hc : X c z ≠ 0) (hzero : MvPolynomial.eval (fun a => X a z) G = 0) :
        planePolynomialEval (Nagata.W27.directChartHom c G) (normalizedCurvePoint X c z) = 0 := by
    …

    Mentions: OAI.Nagata.Workers.W28.planePolynomialEval, OAI.Nagata.W27.directChartHom, OAI.Nagata.Workers.W28.normalizedCurvePoint

  4. theorem OAI.Nagata.Workers.W28.normalizedCurvePoint_equation_locally line 52

    Source documentation

    The homogeneous-to-affine equation holds on an actual neighborhood where the chosen analytic homogeneous coordinate stays nonzero.

    theorem normalizedCurvePoint_equation_locally
        (G : MvPolynomial (Fin 3) ℂ) (k : ℕ) (hG : G.IsHomogeneous k)
        (X : Fin 3 → ℂ → ℂ) (c : Fin 3) (z₀ : ℂ)
        (ha : ContinuousAt (X c) z₀) (hc : X c z₀ ≠ 0)
        (hzero : ∀ᶠ z in 𝓝 z₀, MvPolynomial.eval (fun a => X a z) G = 0) :
        ∀ᶠ z in 𝓝 z₀, planePolynomialEval (Nagata.W27.directChartHom c G)
          (normalizedCurvePoint X c z) = 0 := by
    …

    Mentions: OAI.Nagata.Workers.W28.planePolynomialEval, OAI.Nagata.W27.directChartHom, OAI.Nagata.Workers.W28.normalizedCurvePoint

  5. theorem OAI.Nagata.Workers.W28.homogeneous_normal_frame_identity_plane line 73
  6. theorem OAI.Nagata.Workers.W28.homogeneous_normal_order_of_central_order line 92

    Source documentation

    Central normal order implies actual homogeneous polynomial order on an analytic parametrized curve, with the exact variable degree-d frame factor.

    theorem homogeneous_normal_order_of_central_order
        (I : Finset ℕ) (j : ℕ → ℕ) (T : ℕ → MvPolynomial (Fin 3) ℂ)
        (d k : ℕ) (hhom : ∀ α ∈ I, (T α).IsHomogeneous (d-k*j α))
        (hbound : ∀ α ∈ I, k*j α ≤ d)
        (G : MvPolynomial (Fin 3) ℂ) (hG : G.IsHomogeneous k)
        (X : Fin 3 → ℂ → ℂ) (c : Fin 3) (z₀ w₀ : ℂ)
        (hX : ∀ a, AnalyticAt ℂ (X a) z₀) (hc : X c z₀ ≠ 0)
        (hzero : ∀ᶠ z in 𝓝 z₀, MvPolynomial.eval (fun a => X a z) G = 0)
        (e : OpenPartialHomeomorph ComplexPlane ComplexPlane)
        (he : (e : ComplexPlane → ComplexPlane) = polynomialNormalCoordinates (Nagata.W27.directChartHom c G))
        (hsource : normalizedCurvePoint X c z₀ ∈ e.source) (m : ℕ)
        (horder : HasAnalyticOrderAtLeast (𝕜 := ℂ)
    …

    Mentions: OAI.Nagata.Workers.W28.ComplexPlane, OAI.Nagata.Workers.W28.polynomialNormalCoordinates, OAI.Nagata.W27.directChartHom, OAI.Nagata.Workers.W28.normalizedCurvePoint, OAI.Nagata.Workers.W28.HasAnalyticOrderAtLeast

  7. theorem OAI.Nagata.Workers.W28.analyticAt_curve_swap line 133

    Source documentation

    Swapping actual affine coordinates preserves analyticity of a curve.

    theorem analyticAt_curve_swap (p : ℂ → ComplexPlane) (z₀ : ℂ)
        (hp : AnalyticAt ℂ p z₀) : AnalyticAt ℂ (fun z => (p z).swap) z₀ := by
    …

    Mentions: OAI.Nagata.Workers.W28.ComplexPlane

  8. theorem OAI.Nagata.Workers.W28.homogeneous_normal_order_of_swapped_central_order line 140

    Source documentation

    The alternative tangential coordinate changes neither the homogeneous normal expression nor its variable frame and fiber weights.

    theorem homogeneous_normal_order_of_swapped_central_order
        (I : Finset ℕ) (j : ℕ → ℕ) (T : ℕ → MvPolynomial (Fin 3) ℂ)
        (d k : ℕ) (hhom : ∀ α ∈ I, (T α).IsHomogeneous (d-k*j α))
        (hbound : ∀ α ∈ I, k*j α ≤ d)
        (G : MvPolynomial (Fin 3) ℂ) (hG : G.IsHomogeneous k)
        (X : Fin 3 → ℂ → ℂ) (c : Fin 3) (z₀ w₀ : ℂ)
        (hX : ∀ a, AnalyticAt ℂ (X a) z₀) (hc : X c z₀ ≠ 0)
        (hzero : ∀ᶠ z in 𝓝 z₀, MvPolynomial.eval (fun a => X a z) G = 0)
        (e : OpenPartialHomeomorph ComplexPlane ComplexPlane)
        (he : (e : ComplexPlane → ComplexPlane) = polynomialNormalCoordinates
          (Nagata.Workers.W17.affineSwap (Nagata.W27.directChartHom c G)))
        (hsource : (normalizedCurvePoint X c z₀).swap ∈ e.source) (m : ℕ)
    …

    Mentions: OAI.Nagata.Workers.W28.ComplexPlane, OAI.Nagata.Workers.W28.polynomialNormalCoordinates, OAI.Nagata.Workers.W17.affineSwap, OAI.Nagata.W27.directChartHom, OAI.Nagata.Workers.W28.normalizedCurvePoint