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Atlas.GeometryOfManifolds.code.Integration

structure StokesIntegration {Ω : Type u_1} {VF : Type u_2} [inst : DifferentialFormSpace Ω VF] :
Type u_1

An integration structure on a differential form space supporting Stokes' theorem: provides a top dimension $n$, a wedge-pairing $\langle \alpha, \beta \rangle$ on $p$-forms, an integral $\int : \Omega^n \to \mathbb{R}$, and the Leibniz/integration-by-parts identity $\int (d\alpha) \wedge \beta = (-1)^{p+1} \int \alpha \wedge d\beta$.

Instances For
    def StokesIntegration.inner_prod {Ω : Type u_1} {VF : Type u_2} [inst : DifferentialFormSpace Ω VF] (S : StokesIntegration) (p : ) (α β : Ω p) :

    The $L^2$ inner product on $p$-forms induced by the Hodge-star pairing: $\langle \alpha, \beta \rangle = \int \alpha \wedge \star \beta$.

    Instances For
      theorem StokesIntegration.inner_product_linear {Ω : Type u_1} {VF : Type u_2} [inst : DifferentialFormSpace Ω VF] (S : StokesIntegration) (p : ) (r : ) (α₁ α₂ β : Ω p) :
      S.inner_prod p (r α₁ + α₂) β = r * S.inner_prod p α₁ β + S.inner_prod p α₂ β

      Linearity of the inner product in the first argument: $\langle r\alpha_1 + \alpha_2, \beta \rangle = r\langle \alpha_1, \beta \rangle + \langle \alpha_2, \beta \rangle$.

      theorem StokesIntegration.stokes_adjoint_identity {Ω : Type u_1} {VF : Type u_2} [inst : DifferentialFormSpace Ω VF] (S : StokesIntegration) (p : ) (α : Ω p) (β : Ω (p + 1)) :
      S.inner_prod (p + 1) (DifferentialFormSpace.d VF α) β = (-1) ^ (p + 1) S.integrate (S.wedge_star_d p α β)

      Adjointness from Stokes' theorem: $\langle d\alpha, \beta \rangle = (-1)^{p+1} \int \alpha \wedge d\beta$, identifying $d$ as (up to sign) the formal adjoint to itself in the pairing.