Green's theorem for finite integer-weighted AC families #
The field is localized using every trace and the support of the total winding weight.
Only the total index must vanish outside the domain: individual indices may cancel.
Simultaneous polygonal approximation preserves the total index outside the domain. The actual
polygonal identities pass to the family through boundary and total-weight L¹ convergence.
theorem
TauCeti.Green.green_ac_winding_sum
{ι : Type u_1}
{s : Finset ι}
{γ : ι → ℝ → ℂ}
{a b : ι → ℝ}
{w : ι → ℤ}
{U : Set ℂ}
{P Q : ℂ → ℝ}
(hab : ∀ i ∈ s, a i < b i)
(hγ : ∀ i ∈ s, AbsolutelyContinuousOnInterval (γ i) (a i) (b i))
(hclosed : ∀ i ∈ s, γ i (a i) = γ i (b i))
(hU : IsOpen U)
(htrace : ∀ i ∈ s, γ i '' Set.uIcc (a i) (b i) ⊆ U)
(hP : ContDiffOn ℝ 1 P U)
(hQ : ContDiffOn ℝ 1 Q U)
(hindex : ∀ z ∉ U, ∑ i ∈ s, ↑(w i) * Contour.windingNumber (γ i) (a i) (b i) z = 0)
:
(∀ i ∈ s, IntervalIntegrable (circulationFun P Q (γ i)) MeasureTheory.volume (a i) (b i)) ∧ MeasureTheory.IntegrableOn (fun (z : ℂ) => (∑ i ∈ s, ↑(w i) * windingWeight (γ i) (a i) (b i) z) * curl P Q z) U
MeasureTheory.volume ∧ ∑ i ∈ s, ↑(w i) * ∫ (t : ℝ) in a i..b i, circulationFun P Q (γ i) t = ∫ (z : ℂ) in U, (∑ i ∈ s, ↑(w i) * windingWeight (γ i) (a i) (b i) z) * curl P Q z
Green's theorem for a finite integer-weighted family of closed AC curves. The domain condition concerns the total index, permitting cancellation between curves.