Infinite-dimensional operator ridgelet transform

3.2. The frame operator and the reconstruction formula🔗

Definition3.2.1
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Definition 2.3.1
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Lemma 3.2.4
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L∃∀N

Let \mathcal E_\alpha' be the continuous anti-dual of \mathcal E_\alpha, represented as the continuous conjugate-linear functionals on \mathcal K_\alpha. The Riesz map is J_\alpha f[g]=\langle f,g\rangle_{\mathcal E_\alpha}, with inverse J_\alpha^{-1} from the Riesz representation theorem; the transpose of U_\alpha is U_\alpha'F[g]=\langle F,U_\alpha g\rangle_{L^2(\nu_\alpha)} for F\in L^2(\nu_\alpha), and the frame operator is T_\alpha=U_\alpha'U_\alpha. With R_\rho:\mathcal E_\alpha\to L^2(\lambda_\alpha) the bounded extension of Theorem 2.4.2 (ii) and \operatorname{Ran}R_\rho its range, synthesis with the analysis filter is the transpose S_\rho=R_\rho', (S_\rho\gamma)[g]=\langle\gamma,R_\rho g\rangle_{L^2(\lambda_\alpha)}.

Lean code for Definition3.2.19 definitions
  • complete
    abbrev OperatorRidgelet.SpectralAntiDual.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [MeasurableSpace H]
      [OpensMeasurableSpace H] (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsFiniteMeasure μ] : Type u_1
    abbrev OperatorRidgelet.SpectralAntiDual.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [MeasurableSpace H]
      [OpensMeasurableSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsFiniteMeasure μ] :
      Type u_1
    The continuous anti-dual `𝓔' = 𝒦 →L⋆[ℂ] ℂ` of `𝓔` (represented by `𝒦`): continuous
    conjugate-linear functionals. 
  • def OperatorRidgelet.antiDualConj.{u_1} {E : Type u_1}
      [NormedAddCommGroup E] [NormedSpace  E] (F : E →L⋆[] ) : E →L[] 
    def OperatorRidgelet.antiDualConj.{u_1}
      {E : Type u_1} [NormedAddCommGroup E]
      [NormedSpace  E] (F : E →L⋆[] ) :
      E →L[] 
    The continuous linear functional `g ↦ conj (F g)` of a continuous conjugate-linear
    functional `F`. 
  • def OperatorRidgelet.rieszMap.{u_1} {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H] [MeasurableSpace H] [OpensMeasurableSpace H]
      (μ ν : MeasureTheory.Measure H) [MeasureTheory.IsFiniteMeasure μ] :
      (OperatorRidgelet.spectralRange μ ν) →L[]
        OperatorRidgelet.SpectralAntiDual μ ν
    def OperatorRidgelet.rieszMap.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [MeasurableSpace H]
      [OpensMeasurableSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsFiniteMeasure μ] :
      (OperatorRidgelet.spectralRange μ
            ν) →L[]
        OperatorRidgelet.SpectralAntiDual μ ν
    The Riesz map `J : 𝓔 → 𝓔'`, `J f [g] = ⟨f, g⟩_𝓔` (`eq:riesz-map`), linear in `f` and
    conjugate linear in `g`. 
  • def OperatorRidgelet.rieszInv.{u_1} {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H] [MeasurableSpace H] [OpensMeasurableSpace H]
      (μ ν : MeasureTheory.Measure H) [MeasureTheory.IsFiniteMeasure μ]
      (F : OperatorRidgelet.SpectralAntiDual μ ν) :
      (OperatorRidgelet.spectralRange μ ν)
    def OperatorRidgelet.rieszInv.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [MeasurableSpace H]
      [OpensMeasurableSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsFiniteMeasure μ]
      (F :
        OperatorRidgelet.SpectralAntiDual μ
          ν) :
      (OperatorRidgelet.spectralRange μ ν)
    The inverse Riesz map `J⁻¹ : 𝓔' → 𝓔`: the vector representing a continuous conjugate-linear
    functional (Riesz representation theorem, through `InnerProductSpace.toDual`). 
  • def OperatorRidgelet.transposeEmbed.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [MeasurableSpace H]
      [OpensMeasurableSpace H] (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsFiniteMeasure μ] (F : (MeasureTheory.Lp  2 ν)) :
      OperatorRidgelet.SpectralAntiDual μ ν
    def OperatorRidgelet.transposeEmbed.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [MeasurableSpace H]
      [OpensMeasurableSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsFiniteMeasure μ]
      (F : (MeasureTheory.Lp  2 ν)) :
      OperatorRidgelet.SpectralAntiDual μ ν
    The anti-dual transpose `U' : L²(ν) → 𝓔'` of the unitary `U : 𝓔 → 𝒦 ⊆ L²(ν)`,
    `U' F [g] = ⟨F, U g⟩_{L²(ν)}` (`eq:transpose-analysis`). 
  • def OperatorRidgelet.frameOperator.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [MeasurableSpace H]
      [OpensMeasurableSpace H] (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsFiniteMeasure μ]
      (f : (OperatorRidgelet.spectralRange μ ν)) :
      OperatorRidgelet.SpectralAntiDual μ ν
    def OperatorRidgelet.frameOperator.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [MeasurableSpace H]
      [OpensMeasurableSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsFiniteMeasure μ]
      (f :
        (OperatorRidgelet.spectralRange μ
            ν)) :
      OperatorRidgelet.SpectralAntiDual μ ν
    The frame operator `T = U' U : 𝓔 → 𝓔'`. 
  • def OperatorRidgelet.ridgeletExtension.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [MeasurableSpace H]
      [OpensMeasurableSpace H] (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsFiniteMeasure μ] (ρ :   ) :
      (OperatorRidgelet.spectralRange μ ν) →L[]
        (MeasureTheory.Lp  2 (OperatorRidgelet.parameterMeasure ν))
    def OperatorRidgelet.ridgeletExtension.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [MeasurableSpace H]
      [OpensMeasurableSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsFiniteMeasure μ]
      (ρ :   ) :
      (OperatorRidgelet.spectralRange μ
            ν) →L[]
        (MeasureTheory.Lp  2
            (OperatorRidgelet.parameterMeasure
              ν))
    The bounded extension `R_ρ : 𝓔 → L²(λ)` of Theorem `thm:B`(ii), represented on `𝒦`: the
    continuous linear map that agrees `λ`-almost everywhere with `f ↦ R_ρ f` on `U(𝒟)`, when one
    exists, and `0` otherwise. 
  • def OperatorRidgelet.ridgeletRange.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [MeasurableSpace H]
      [OpensMeasurableSpace H] (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsFiniteMeasure μ] (ρ :   ) :
      Submodule 
        (MeasureTheory.Lp  2 (OperatorRidgelet.parameterMeasure ν))
    def OperatorRidgelet.ridgeletRange.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [MeasurableSpace H]
      [OpensMeasurableSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsFiniteMeasure μ]
      (ρ :   ) :
      Submodule 
        (MeasureTheory.Lp  2
            (OperatorRidgelet.parameterMeasure
              ν))
    The range `Ran R_ρ ⊆ L²(λ)` of the extended transform. 
  • def OperatorRidgelet.synthesis.{u_1} {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H] [MeasurableSpace H] [OpensMeasurableSpace H]
      (μ ν : MeasureTheory.Measure H) [MeasureTheory.IsFiniteMeasure μ]
      (ρ :   )
      (γ : (MeasureTheory.Lp  2 (OperatorRidgelet.parameterMeasure ν))) :
      OperatorRidgelet.SpectralAntiDual μ ν
    def OperatorRidgelet.synthesis.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [MeasurableSpace H]
      [OpensMeasurableSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsFiniteMeasure μ]
      (ρ :   )
      (γ :
        (MeasureTheory.Lp  2
            (OperatorRidgelet.parameterMeasure
              ν))) :
      OperatorRidgelet.SpectralAntiDual μ ν
    The synthesis operator `S_ρ = R_ρ' : L²(λ) → 𝓔'`, the anti-dual transpose of the extended
    transform: `(S_ρ γ)[g] = ⟨γ, R_ρ g⟩_{L²(λ)}` (`eq:weak-synthesis`). 
Definition3.2.2
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Definition 2.2.5
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Proposition 3.2.6
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L∃∀N

For \gamma\in L^2(\lambda_\alpha), define the backprojection as \Lambda_\rho=W_\rho^*. By Lemma 2.2.8, it is represented by the ray average \Lambda_\rho\gamma(\xi)=\frac1{2\pi}\int_{\mathbb R}\overline{\widehat\rho(\omega)}\,|\omega|^{-\alpha}\,\widehat\gamma(-\xi/\omega,\omega)\,\mathrm d\omega, computed from any jointly strongly measurable partial Fourier representative supplied by Lemma 2.2.7. The integral converges absolutely for almost every \xi, and its L^2(\nu_\alpha) class is independent of the representative. With P_{\mathcal K_\alpha} the orthogonal projection onto \mathcal K_\alpha, the coefficient projection is \Pi_\rho=C^{-1}W_\rho P_{\mathcal K_\alpha}\Lambda_\rho.

Lean code for Definition3.2.24 definitions
  • def OperatorRidgelet.backprojectionOf.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] (α : ) (ρ :   )
      (Φ : H    ) (ξ : H) : 
    def OperatorRidgelet.backprojectionOf.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H] (α : )
      (ρ :   ) (Φ : H    ) (ξ : H) : 
    The backprojection (ray average, `eq:ray-average`) of a partial bias-Fourier representative
    `Φ` of a coefficient: `Λ_ρ Φ (ξ) = (2π)⁻¹ ∫ conj(ρ̂(ω)) |ω|^{-α} Φ(-ξ/ω, ω) dω`. 
  • def OperatorRidgelet.backprojection.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [MeasurableSpace H]
      (α : ) (ν : MeasureTheory.Measure H) (ρ :   ) (γ : H ×   ) :
      H  
    def OperatorRidgelet.backprojection.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [MeasurableSpace H] (α : )
      (ν : MeasureTheory.Measure H)
      (ρ :   ) (γ : H ×   ) : H  
    The backprojection `Λ_ρ γ` of a coefficient `γ`, computed from a jointly measurable partial
    bias-Fourier representative of `γ` (`HasBiasFourier`), and `0` if there is none.
    
    `HasBiasFourier` requires the representative to be square integrable along `ν`-almost every
    ray, which pins it down up to a null set on almost every ray (`HasBiasFourier.ae_ae_eq`), and
    the ray substitution `(a, ω) ↦ (-ωa, ω)` preserves null sets by homogeneity; hence the ray
    average does not depend on the chosen representative as an element of `L²(ν)`
    (`prop_coefficient_projection_ii`).  For `γ ∈ L²(λ)` a jointly measurable representative exists
    (`exists_measurable_hasBiasFourier`), so the junk value is never taken on `L²(λ)`. 
  • def OperatorRidgelet.backprojectionLp.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [MeasurableSpace H]
      (α : ) (ν : MeasureTheory.Measure H) (ρ :   ) (γ : H ×   ) :
      (MeasureTheory.Lp  2 ν)
    def OperatorRidgelet.backprojectionLp.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [MeasurableSpace H] (α : )
      (ν : MeasureTheory.Measure H)
      (ρ :   ) (γ : H ×   ) :
      (MeasureTheory.Lp  2 ν)
    The backprojection `Λ_ρ γ` as an element of `L²(ν)` (`0` if it is not square
    integrable). 
  • def OperatorRidgelet.coefficientProjection.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [MeasurableSpace H]
      [OpensMeasurableSpace H] (α : ) (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsFiniteMeasure μ] (ρ :   ) (γ : H ×   ) :
      (MeasureTheory.Lp  2 (OperatorRidgelet.parameterMeasure ν))
    def OperatorRidgelet.coefficientProjection.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [MeasurableSpace H]
      [OpensMeasurableSpace H] (α : )
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsFiniteMeasure μ]
      (ρ :   ) (γ : H ×   ) :
      (MeasureTheory.Lp  2
          (OperatorRidgelet.parameterMeasure
            ν))
    The coefficient projection `Π_ρ = C⁻¹ W_ρ P_𝒦 Λ_ρ` (`eq:coefficient-projection`), with
    `P_𝒦` the orthogonal projection of `L²(ν)` onto `𝒦`. 
Definition3.2.3
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Definition 2.1.1
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Lemma 3.2.5
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L∃∀N

For f\in L^2(\mu_Q), \xi\ne0, and \tau(\xi)=\langle Q\xi,\xi\rangle^{1/2}, the analytic continuation z\mapsto\mathcal G_Qf(z\xi)=\int_Hf(x)e^{-iz\langle x,\xi\rangle}\mu_Q(\mathrm dx) and the entire function G_f(z\xi)=e^{z^2\tau(\xi)^2/2}\mathcal G_Qf(z\xi); the Hermite coefficients \mathbb E_{\mu_Q}[f\,\mathrm{He}_n(\langle x,\xi\rangle/\tau(\xi))] with the probabilists' Hermite polynomials; and \Delta_Q, the inverse of \mathcal G_Q on its range on \mathcal D_\alpha, chosen as the element of \mathcal D_\alpha with the given transform.

Lean code for Definition3.2.34 definitions
  • def OperatorRidgelet.gaussFourierLine.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [MeasurableSpace H]
      (μ : MeasureTheory.Measure H) (f : H  ) (ξ : H) (z : ) : 
    def OperatorRidgelet.gaussFourierLine.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [MeasurableSpace H]
      (μ : MeasureTheory.Measure H)
      (f : H  ) (ξ : H) (z : ) : 
    The analytic continuation `z ↦ 𝒢_μ f(zξ) = ∫ f(x) e^{-iz⟪x,ξ⟫} μ(dx)` of the weighted Fourier
    transform along the ray through `ξ` to complex `z`. 
  • def OperatorRidgelet.hermiteExtension.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [MeasurableSpace H]
      (μ : MeasureTheory.Measure H) (Q : H →L[] H) (f : H  ) (ξ : H)
      (z : ) : 
    def OperatorRidgelet.hermiteExtension.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [MeasurableSpace H]
      (μ : MeasureTheory.Measure H)
      (Q : H →L[] H) (f : H  ) (ξ : H)
      (z : ) : 
    The entire function `G_f(zξ) = e^{z²τ(ξ)²/2} 𝒢_μ f(zξ)` of Lemma `lem:hermite-totality`,
    with `τ(ξ)² = ⟪Qξ,ξ⟫`. 
  • def OperatorRidgelet.hermiteCoefficient.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [MeasurableSpace H]
      (μ : MeasureTheory.Measure H) (Q : H →L[] H) (f : H  ) (ξ : H)
      (n : ) : 
    def OperatorRidgelet.hermiteCoefficient.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [MeasurableSpace H]
      (μ : MeasureTheory.Measure H)
      (Q : H →L[] H) (f : H  ) (ξ : H)
      (n : ) : 
    The Hermite coefficient `E_μ[f(x) He_n(⟪x,ξ⟫/τ(ξ))]`, `τ(ξ) = ⟪Qξ,ξ⟫^{1/2}`, with the
    probabilists' Hermite polynomials `Polynomial.hermite`. 
  • def OperatorRidgelet.gaussFourierInv.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [MeasurableSpace H]
      [OpensMeasurableSpace H] (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsFiniteMeasure μ] (G : H  ) :
      (MeasureTheory.Lp  2 μ)
    def OperatorRidgelet.gaussFourierInv.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [MeasurableSpace H]
      [OpensMeasurableSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsFiniteMeasure μ]
      (G : H  ) : (MeasureTheory.Lp  2 μ)
    The inverse `Δ_Q` of `𝒢_μ` on its range on `𝒟`: the element `f ∈ 𝒟` with `𝒢_μ f = G` when
    one exists (it is unique by Theorem `thm:C`(iv)), and `0` otherwise. 
Lemma3.2.4
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Definition 1.1.2
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used by 1L∃∀N

Let \rho\in\mathcal S(\mathbb R) be real and \gamma\in L^1(\lambda_\alpha)\cap L^2(\lambda_\alpha). Then the integral network S_\rho[\gamma\lambda_\alpha] is a bounded Borel function on H (i), and for every g\in\mathcal D_\alpha, \langle\gamma,R_\rho g\rangle_{L^2(\lambda_\alpha)}=\int_HS_\rho[\gamma\lambda_\alpha](x)\,\overline{g(x)}\,\mu_Q(\mathrm dx) (ii), so the synthesis functional S_\rho\gamma is the integral network paired with g through \mu_Q.

Lean code for Lemma3.2.42 theorems
  • complete
    theorem OperatorRidgelet.Paper.lem_weak_equals_strong_i.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [CompleteSpace H]
      [SecondCountableTopology H] [MeasurableSpace H] [BorelSpace H]
      (ν : MeasureTheory.Measure H) [MeasureTheory.SigmaFinite ν]
      (ρ : SchwartzMap  )
      (γ : (MeasureTheory.Lp  2 (OperatorRidgelet.parameterMeasure ν)))
      ( :
        MeasureTheory.Integrable (↑γ)
          (OperatorRidgelet.parameterMeasure ν)) :
      Measurable
          (OperatorRidgelet.integralNetworkDensity (fun t => (ρ t))
            (OperatorRidgelet.parameterMeasure ν) γ) 
         M,
           (x : H),
            OperatorRidgelet.integralNetworkDensity (fun t => (ρ t))
                  (OperatorRidgelet.parameterMeasure ν) (↑γ) x 
              M
    theorem OperatorRidgelet.Paper.lem_weak_equals_strong_i.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      (ν : MeasureTheory.Measure H)
      [MeasureTheory.SigmaFinite ν]
      (ρ : SchwartzMap  )
      (γ :
        (MeasureTheory.Lp  2
            (OperatorRidgelet.parameterMeasure
              ν)))
      ( :
        MeasureTheory.Integrable (↑γ)
          (OperatorRidgelet.parameterMeasure
            ν)) :
      Measurable
          (OperatorRidgelet.integralNetworkDensity
            (fun t => (ρ t))
            (OperatorRidgelet.parameterMeasure
              ν)
            γ) 
         M,
           (x : H),
            OperatorRidgelet.integralNetworkDensity
                  (fun t => (ρ t))
                  (OperatorRidgelet.parameterMeasure
                    ν)
                  (↑γ) x 
              M
    **Lemma [lem:weak-equals-strong]** Synthesis of an integrable coefficient is the integral
    network.  For real Schwartz `ρ` and `γ ∈ L¹(λ_α) ∩ L²(λ_α)`, the integral network
    `S_ρ[γ λ_α]` is a bounded Borel function on `H`. 
  • complete
    theorem OperatorRidgelet.Paper.lem_weak_equals_strong_ii.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [CompleteSpace H]
      [SecondCountableTopology H] [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H) [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν] (ρ : SchwartzMap  )
      (γ : (MeasureTheory.Lp  2 (OperatorRidgelet.parameterMeasure ν)))
      ( :
        MeasureTheory.Integrable (↑γ)
          (OperatorRidgelet.parameterMeasure ν))
      (g : (OperatorRidgelet.spectralCore μ ν)) :
       (p : H × ),
          γ p *
            (starRingEnd )
              (OperatorRidgelet.ridgelet μ (⇑ρ) (↑g)
                p) OperatorRidgelet.parameterMeasure ν =
         (x : H),
          OperatorRidgelet.integralNetworkDensity (fun t => (ρ t))
              (OperatorRidgelet.parameterMeasure ν) (↑γ) x *
            (starRingEnd ) (g x) μ
    theorem OperatorRidgelet.Paper.lem_weak_equals_strong_ii.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν]
      (ρ : SchwartzMap  )
      (γ :
        (MeasureTheory.Lp  2
            (OperatorRidgelet.parameterMeasure
              ν)))
      ( :
        MeasureTheory.Integrable (↑γ)
          (OperatorRidgelet.parameterMeasure
            ν))
      (g :
        (OperatorRidgelet.spectralCore μ
            ν)) :
       (p : H × ),
          γ p *
            (starRingEnd )
              (OperatorRidgelet.ridgelet μ
                (⇑ρ) (↑g)
                p) OperatorRidgelet.parameterMeasure
            ν =
         (x : H),
          OperatorRidgelet.integralNetworkDensity
              (fun t => (ρ t))
              (OperatorRidgelet.parameterMeasure
                ν)
              (↑γ) x *
            (starRingEnd ) (g x) μ
    **Lemma [lem:weak-equals-strong]** Synthesis of an integrable coefficient is the integral
    network.  For every `g ∈ 𝒟_α`, the synthesis functional `(S_ρ γ)[g] = ⟨γ, R_ρ g⟩_{L²(λ_α)}`
    of `eq:weak-synthesis` equals `∫ S_ρ[γ λ_α](x) conj(g(x)) μ_Q(dx)`. 
Proof for Lemma 3.2.4
uses 0

|S_\rho[\gamma\lambda_\alpha]|\le\|\gamma\|_{L^1}\|\rho\|_\infty, and the double integral of |\gamma||g||\rho(\langle a,x\rangle+c)| is at most \|\gamma\|_{L^1}\|\rho\|_\infty\|g\|_{L^1(\mu_Q)}, so Fubini applies; \rho is real.

Lemma3.2.5
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Definition 2.1.1
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used by 1L∃∀N

For f\in L^2(\mu_Q) and \xi\ne0, the function z\mapsto G_f(z\xi) is entire (i), G_f(z\xi)=\sum_{n\ge0}\frac{(-iz\tau(\xi))^n}{n!}\mathbb E_{\mu_Q}[f\,\mathrm{He}_n(\langle x,\xi\rangle/\tau(\xi))] (ii) with locally uniform convergence (iii), |G_f(z\xi)|\le\|f\|_{L^2(\mu_Q)}e^{|z|^2\tau(\xi)^2/2} (iv), and the Hermite inversion formula \mathbb E_{\mu_Q}[f\,\mathrm{He}_n(\langle x,\xi\rangle/\tau(\xi))]=\frac{i^n}{\tau(\xi)^n}\frac{\mathrm d^n}{\mathrm dt^n}\bigl(e^{t^2\tau(\xi)^2/2}\mathcal G_Qf(t\xi)\bigr)\big|_{t=0} holds (v). The coefficients, over all \xi\ne0 and n, determine f in L^2(\mu_Q) (vi).

Lean code for Lemma3.2.56 theorems
  • complete
    theorem OperatorRidgelet.Paper.lem_hermite_totality_i.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [CompleteSpace H]
      [SecondCountableTopology H] [MeasurableSpace H] [BorelSpace H]
      {Q : H →L[] H} (hQ : OperatorRidgelet.IsTraceClassCovariance Q)
      (μ : MeasureTheory.Measure H) [MeasureTheory.IsProbabilityMeasure μ]
      ( : OperatorRidgelet.IsCenteredGaussian Q μ) (f : H  )
      (hf : MeasureTheory.MemLp f 2 μ) (ξ : H) ( : ξ  0) :
      Differentiable  (OperatorRidgelet.hermiteExtension μ Q f ξ)
    theorem OperatorRidgelet.Paper.lem_hermite_totality_i.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      {Q : H →L[] H}
      (hQ :
        OperatorRidgelet.IsTraceClassCovariance
          Q)
      (μ : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      ( :
        OperatorRidgelet.IsCenteredGaussian Q
          μ)
      (f : H  )
      (hf : MeasureTheory.MemLp f 2 μ) (ξ : H)
      ( : ξ  0) :
      Differentiable 
        (OperatorRidgelet.hermiteExtension μ Q
          f ξ)
    **Lemma [lem:hermite-totality]** Entire extension and totality of the Hermite coefficients.
    For `f ∈ L²(μ_Q)` and `ξ ≠ 0`, `z ↦ G_f(zξ) = e^{z²τ(ξ)²/2} 𝒢_Q f(zξ)` is entire. 
  • complete
    theorem OperatorRidgelet.Paper.lem_hermite_totality_ii.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [CompleteSpace H]
      [SecondCountableTopology H] [MeasurableSpace H] [BorelSpace H]
      {Q : H →L[] H} (hQ : OperatorRidgelet.IsTraceClassCovariance Q)
      (μ : MeasureTheory.Measure H) [MeasureTheory.IsProbabilityMeasure μ]
      ( : OperatorRidgelet.IsCenteredGaussian Q μ) (f : H  )
      (hf : MeasureTheory.MemLp f 2 μ) (ξ : H) ( : ξ  0) (z : ) :
      HasSum
        (fun n =>
          (-(Complex.I * z * (inner  (Q ξ) ξ))) ^ n / n.factorial *
            OperatorRidgelet.hermiteCoefficient μ Q f ξ n)
        (OperatorRidgelet.hermiteExtension μ Q f ξ z)
    theorem OperatorRidgelet.Paper.lem_hermite_totality_ii.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      {Q : H →L[] H}
      (hQ :
        OperatorRidgelet.IsTraceClassCovariance
          Q)
      (μ : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      ( :
        OperatorRidgelet.IsCenteredGaussian Q
          μ)
      (f : H  )
      (hf : MeasureTheory.MemLp f 2 μ) (ξ : H)
      ( : ξ  0) (z : ) :
      HasSum
        (fun n =>
          (-(Complex.I * z *
                    (inner  (Q ξ) ξ))) ^
                n /
              n.factorial *
            OperatorRidgelet.hermiteCoefficient
              μ Q f ξ n)
        (OperatorRidgelet.hermiteExtension μ Q
          f ξ z)
    **Lemma [lem:hermite-totality]** Entire extension and totality of the Hermite coefficients.
    The Hermite series `G_f(zξ) = ∑ₙ (-izτ(ξ))^n/n! E_{μ_Q}[f He_n(⟨x,ξ⟩/τ(ξ))]` converges for every
    `z`. 
  • complete
    theorem OperatorRidgelet.Paper.lem_hermite_totality_iii.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [CompleteSpace H]
      [SecondCountableTopology H] [MeasurableSpace H] [BorelSpace H]
      {Q : H →L[] H} (hQ : OperatorRidgelet.IsTraceClassCovariance Q)
      (μ : MeasureTheory.Measure H) [MeasureTheory.IsProbabilityMeasure μ]
      ( : OperatorRidgelet.IsCenteredGaussian Q μ) (f : H  )
      (hf : MeasureTheory.MemLp f 2 μ) (ξ : H) ( : ξ  0) :
      TendstoLocallyUniformly
        (fun N z =>
           n  Finset.range N,
            (-(Complex.I * z * (inner  (Q ξ) ξ))) ^ n / n.factorial *
              OperatorRidgelet.hermiteCoefficient μ Q f ξ n)
        (OperatorRidgelet.hermiteExtension μ Q f ξ) Filter.atTop
    theorem OperatorRidgelet.Paper.lem_hermite_totality_iii.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      {Q : H →L[] H}
      (hQ :
        OperatorRidgelet.IsTraceClassCovariance
          Q)
      (μ : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      ( :
        OperatorRidgelet.IsCenteredGaussian Q
          μ)
      (f : H  )
      (hf : MeasureTheory.MemLp f 2 μ) (ξ : H)
      ( : ξ  0) :
      TendstoLocallyUniformly
        (fun N z =>
           n  Finset.range N,
            (-(Complex.I * z *
                      (inner  (Q ξ) ξ))) ^
                  n /
                n.factorial *
              OperatorRidgelet.hermiteCoefficient
                μ Q f ξ n)
        (OperatorRidgelet.hermiteExtension μ Q
          f ξ)
        Filter.atTop
    **Lemma [lem:hermite-totality]** Entire extension and totality of the Hermite coefficients.
    The Hermite series converges locally uniformly in `z`. 
  • complete
    theorem OperatorRidgelet.Paper.lem_hermite_totality_iv.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [CompleteSpace H]
      [SecondCountableTopology H] [MeasurableSpace H] [BorelSpace H]
      {Q : H →L[] H} (hQ : OperatorRidgelet.IsTraceClassCovariance Q)
      (μ : MeasureTheory.Measure H) [MeasureTheory.IsProbabilityMeasure μ]
      ( : OperatorRidgelet.IsCenteredGaussian Q μ) (f : H  )
      (hf : MeasureTheory.MemLp f 2 μ) (ξ : H) ( : ξ  0) (z : ) :
      OperatorRidgelet.hermiteExtension μ Q f ξ z 
        ( (x : H), f x ^ 2 μ) *
          Real.exp (z ^ 2 * inner  (Q ξ) ξ / 2)
    theorem OperatorRidgelet.Paper.lem_hermite_totality_iv.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      {Q : H →L[] H}
      (hQ :
        OperatorRidgelet.IsTraceClassCovariance
          Q)
      (μ : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      ( :
        OperatorRidgelet.IsCenteredGaussian Q
          μ)
      (f : H  )
      (hf : MeasureTheory.MemLp f 2 μ) (ξ : H)
      ( : ξ  0) (z : ) :
      OperatorRidgelet.hermiteExtension μ Q f
            ξ z 
        ( (x : H), f x ^ 2 μ) *
          Real.exp
            (z ^ 2 * inner  (Q ξ) ξ / 2)
    **Lemma [lem:hermite-totality]** Entire extension and totality of the Hermite coefficients.
    The bound `|G_f(zξ)| ≤ ‖f‖_{L²(μ_Q)} e^{|z|²τ(ξ)²/2}`. 
  • complete
    theorem OperatorRidgelet.Paper.lem_hermite_totality_v.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [CompleteSpace H]
      [SecondCountableTopology H] [MeasurableSpace H] [BorelSpace H]
      {Q : H →L[] H} (hQ : OperatorRidgelet.IsTraceClassCovariance Q)
      (μ : MeasureTheory.Measure H) [MeasureTheory.IsProbabilityMeasure μ]
      ( : OperatorRidgelet.IsCenteredGaussian Q μ) (f : H  )
      (hf : MeasureTheory.MemLp f 2 μ) (ξ : H) ( : ξ  0) (n : ) :
      OperatorRidgelet.hermiteCoefficient μ Q f ξ n =
        Complex.I ^ n / (inner  (Q ξ) ξ) ^ n *
          iteratedDeriv n
            (fun t => OperatorRidgelet.hermiteExtension μ Q f ξ t) 0
    theorem OperatorRidgelet.Paper.lem_hermite_totality_v.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      {Q : H →L[] H}
      (hQ :
        OperatorRidgelet.IsTraceClassCovariance
          Q)
      (μ : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      ( :
        OperatorRidgelet.IsCenteredGaussian Q
          μ)
      (f : H  )
      (hf : MeasureTheory.MemLp f 2 μ) (ξ : H)
      ( : ξ  0) (n : ) :
      OperatorRidgelet.hermiteCoefficient μ Q
          f ξ n =
        Complex.I ^ n /
            (inner  (Q ξ) ξ) ^ n *
          iteratedDeriv n
            (fun t =>
              OperatorRidgelet.hermiteExtension
                μ Q f ξ t)
            0
    **Lemma [lem:hermite-totality]** Entire extension and totality of the Hermite coefficients.
    The Hermite inversion formula `eq:hermite-inversion` holds for `f ∈ L²(μ_Q)` and `ξ ≠ 0`. 
  • complete
    theorem OperatorRidgelet.Paper.lem_hermite_totality_vi.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [CompleteSpace H]
      [SecondCountableTopology H] [MeasurableSpace H] [BorelSpace H]
      [Nontrivial H] {Q : H →L[] H}
      (hQ : OperatorRidgelet.IsTraceClassCovariance Q)
      (μ : MeasureTheory.Measure H) [MeasureTheory.IsProbabilityMeasure μ]
      ( : OperatorRidgelet.IsCenteredGaussian Q μ) (f : H  )
      (hf : MeasureTheory.MemLp f 2 μ) (g : H  ) :
      MeasureTheory.MemLp g 2 μ 
        (∀ (ξ : H),
            ξ  0 
               (n : ),
                OperatorRidgelet.hermiteCoefficient μ Q f ξ n =
                  OperatorRidgelet.hermiteCoefficient μ Q g ξ n) 
          f =ᵐ[μ] g
    theorem OperatorRidgelet.Paper.lem_hermite_totality_vi.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      [Nontrivial H] {Q : H →L[] H}
      (hQ :
        OperatorRidgelet.IsTraceClassCovariance
          Q)
      (μ : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      ( :
        OperatorRidgelet.IsCenteredGaussian Q
          μ)
      (f : H  )
      (hf : MeasureTheory.MemLp f 2 μ)
      (g : H  ) :
      MeasureTheory.MemLp g 2 μ 
        (∀ (ξ : H),
            ξ  0 
               (n : ),
                OperatorRidgelet.hermiteCoefficient
                    μ Q f ξ n =
                  OperatorRidgelet.hermiteCoefficient
                    μ Q g ξ n) 
          f =ᵐ[μ] g
    **Lemma [lem:hermite-totality]** Entire extension and totality of the Hermite coefficients.
    The Hermite coefficients over all `ξ ≠ 0` and `n` determine `f` in `L²(μ_Q)`. 
Proof for Lemma 3.2.5
uses 0

The generating function e^{tY-t^2/2}=\sum_n\mathrm{He}_n(Y)t^n/n! of a standard normal Y converges in L^2 locally uniformly in t\in\mathbb C; pairing with f gives the series, the bound, and termwise differentiation. For totality, finite products of Hermite polynomials in independent coordinates form a complete orthogonal system (the Wiener–Itô chaos decomposition), and polarization of Wick powers expresses them through the directional Wick powers.

Proposition3.2.6
Statement uses 5
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Lemma 2.1.4
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used by 1L∃∀N

Let \rho be \alpha-admissible with C=(\!(\rho,\rho)\!)_\alpha and \mathcal Y=L^2(\lambda_\alpha). The ray-average integral defining \Lambda_\rho\gamma converges absolutely for \nu_\alpha-almost every \xi (i), is independent as an L^2 class of the jointly measurable Fourier representative (ii), and satisfies \|\Lambda_\rho\gamma\|_{L^2(\nu_\alpha)}\le\sqrt C\|\gamma\|_{\mathcal Y} (iii); \Lambda_\rho is the Hilbert adjoint of W_\rho (iv) and \Lambda_\rho W_\rho=C\,\mathrm{Id} (v). The operator C^{-1}W_\rho\Lambda_\rho projects onto W_\rho L^2(\nu_\alpha). The operator \Pi_\rho=C^{-1}W_\rho P_{\mathcal K_\alpha}\Lambda_\rho is the orthogonal projection onto \operatorname{Ran}R_\rho (vi), the minimum-norm solution of S_\rho\gamma=F\in\mathcal E_\alpha' is C^{-1}R_\rho J_\alpha^{-1}F (vii), and all solutions differ from it by an element of (\operatorname{Ran}R_\rho)^\perp (viii).

Lean code for Proposition3.2.68 theorems
  • complete
    theorem OperatorRidgelet.Paper.prop_coefficient_projection_i.{u_1}
      {H : Type u_1} [NormedAddCommGroup H] [InnerProductSpace  H]
      [CompleteSpace H] [SecondCountableTopology H] [MeasurableSpace H]
      [BorelSpace H] (ν : MeasureTheory.Measure H)
      [MeasureTheory.SigmaFinite ν] [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α) ( : OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  ) ( : OperatorRidgelet.IsAdmissible α ρ)
      (γ : (MeasureTheory.Lp  2 (OperatorRidgelet.parameterMeasure ν)))
      (Φ : H    ) ( : Measurable (Function.uncurry Φ))
      (hγΦ : OperatorRidgelet.HasBiasFourier ν (↑γ) Φ) :
      ∀ᵐ (ξ : H) ν,
        MeasureTheory.Integrable
          (fun ω =>
            (starRingEnd ) (OperatorRidgelet.filterFourier (⇑ρ) ω) *
                (|ω| ^ (-α)) *
              Φ (-(ω⁻¹  ξ)) ω)
          MeasureTheory.volume
    theorem OperatorRidgelet.Paper.prop_coefficient_projection_i.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      (ν : MeasureTheory.Measure H)
      [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α)
      ( :
        OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ)
      (γ :
        (MeasureTheory.Lp  2
            (OperatorRidgelet.parameterMeasure
              ν)))
      (Φ : H    )
      ( : Measurable (Function.uncurry Φ))
      (hγΦ :
        OperatorRidgelet.HasBiasFourier ν
          (↑γ) Φ) :
      ∀ᵐ (ξ : H) ν,
        MeasureTheory.Integrable
          (fun ω =>
            (starRingEnd )
                  (OperatorRidgelet.filterFourier
                    (⇑ρ) ω) *
                (|ω| ^ (-α)) *
              Φ (-(ω⁻¹  ξ)) ω)
          MeasureTheory.volume
    **Proposition [prop:coefficient-projection]** Bounded backprojection and orthogonal range
    projection.  For `γ ∈ L²(λ_α)` and a jointly measurable partial bias-Fourier representative
    `Φ` of `γ`, the ray-average integral `eq:ray-average` converges absolutely for `ν_α`-almost
    every `ξ`. 
  • complete
    theorem OperatorRidgelet.Paper.prop_coefficient_projection_ii.{u_1}
      {H : Type u_1} [NormedAddCommGroup H] [InnerProductSpace  H]
      [CompleteSpace H] [SecondCountableTopology H] [MeasurableSpace H]
      [BorelSpace H] (ν : MeasureTheory.Measure H)
      [MeasureTheory.SigmaFinite ν] [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α) ( : OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  ) ( : OperatorRidgelet.IsAdmissible α ρ)
      (γ : (MeasureTheory.Lp  2 (OperatorRidgelet.parameterMeasure ν)))
      (Φ Φ' : H    ) ( : Measurable (Function.uncurry Φ))
      (hΦ' : Measurable (Function.uncurry Φ'))
      (hγΦ : OperatorRidgelet.HasBiasFourier ν (↑γ) Φ)
      (hγΦ' : OperatorRidgelet.HasBiasFourier ν (↑γ) Φ') :
      OperatorRidgelet.backprojectionOf α (⇑ρ) Φ =ᵐ[ν]
        OperatorRidgelet.backprojectionOf α (⇑ρ) Φ'
    theorem OperatorRidgelet.Paper.prop_coefficient_projection_ii.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      (ν : MeasureTheory.Measure H)
      [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α)
      ( :
        OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ)
      (γ :
        (MeasureTheory.Lp  2
            (OperatorRidgelet.parameterMeasure
              ν)))
      (Φ Φ' : H    )
      ( : Measurable (Function.uncurry Φ))
      (hΦ' : Measurable (Function.uncurry Φ'))
      (hγΦ :
        OperatorRidgelet.HasBiasFourier ν
          (↑γ) Φ)
      (hγΦ' :
        OperatorRidgelet.HasBiasFourier ν
          (↑γ) Φ') :
      OperatorRidgelet.backprojectionOf α (⇑ρ)
          Φ =ᵐ[ν]
        OperatorRidgelet.backprojectionOf α
          (⇑ρ) Φ'
    **Proposition [prop:coefficient-projection]** Bounded backprojection and orthogonal range
    projection.  As an `L²(ν_α)` class, `Λ_ρ γ` does not depend on the jointly measurable
    Fourier representative of `γ`. 
  • complete
    theorem OperatorRidgelet.Paper.prop_coefficient_projection_iii.{u_1}
      {H : Type u_1} [NormedAddCommGroup H] [InnerProductSpace  H]
      [CompleteSpace H] [SecondCountableTopology H] [MeasurableSpace H]
      [BorelSpace H] (ν : MeasureTheory.Measure H)
      [MeasureTheory.SigmaFinite ν] [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α) ( : OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  ) ( : OperatorRidgelet.IsAdmissible α ρ)
      (γ : (MeasureTheory.Lp  2 (OperatorRidgelet.parameterMeasure ν))) :
      MeasureTheory.MemLp (OperatorRidgelet.backprojection α ν ρ γ) 2 ν 
         (ξ : H),
            OperatorRidgelet.backprojection α ν (⇑ρ) (↑γ) ξ ^ 2 ν 
          OperatorRidgelet.admissibilityConst α ρ * γ ^ 2
    theorem OperatorRidgelet.Paper.prop_coefficient_projection_iii.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      (ν : MeasureTheory.Measure H)
      [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α)
      ( :
        OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ)
      (γ :
        (MeasureTheory.Lp  2
            (OperatorRidgelet.parameterMeasure
              ν))) :
      MeasureTheory.MemLp
          (OperatorRidgelet.backprojection α ν
            ρ γ)
          2 ν 
         (ξ : H),
            OperatorRidgelet.backprojection α
                  ν (⇑ρ) (↑γ) ξ ^
              2 ν 
          OperatorRidgelet.admissibilityConst
              α ρ *
            γ ^ 2
    **Proposition [prop:coefficient-projection]** Bounded backprojection and orthogonal range
    projection.  `Λ_ρ γ ∈ L²(ν_α)` with `‖Λ_ρ γ‖_{L²(ν_α)} ≤ √C ‖γ‖_𝒴`, `C = C^{(α)}_ρ`. 
  • complete
    theorem OperatorRidgelet.Paper.prop_coefficient_projection_iv.{u_1}
      {H : Type u_1} [NormedAddCommGroup H] [InnerProductSpace  H]
      [CompleteSpace H] [SecondCountableTopology H] [MeasurableSpace H]
      [BorelSpace H] (ν : MeasureTheory.Measure H)
      [MeasureTheory.SigmaFinite ν] [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α) ( : OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  ) ( : OperatorRidgelet.IsAdmissible α ρ)
      (γ : (MeasureTheory.Lp  2 (OperatorRidgelet.parameterMeasure ν)))
      (F : H  ) :
      Measurable F 
        MeasureTheory.MemLp F 2 ν 
           (p : H × ),
              γ p *
                (starRingEnd )
                  ((OperatorRidgelet.spectralCoefficient ν (⇑ρ) F)
                    p) OperatorRidgelet.parameterMeasure ν =
             (ξ : H),
              OperatorRidgelet.backprojection α ν (⇑ρ) (↑γ) ξ *
                (starRingEnd ) (F ξ) ν
    theorem OperatorRidgelet.Paper.prop_coefficient_projection_iv.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      (ν : MeasureTheory.Measure H)
      [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α)
      ( :
        OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ)
      (γ :
        (MeasureTheory.Lp  2
            (OperatorRidgelet.parameterMeasure
              ν)))
      (F : H  ) :
      Measurable F 
        MeasureTheory.MemLp F 2 ν 
           (p : H × ),
              γ p *
                (starRingEnd )
                  ((OperatorRidgelet.spectralCoefficient
                          ν (⇑ρ) F)
                    p) OperatorRidgelet.parameterMeasure
                ν =
             (ξ : H),
              OperatorRidgelet.backprojection
                  α ν (⇑ρ) (↑γ) ξ *
                (starRingEnd ) (F ξ) ν
    **Proposition [prop:coefficient-projection]** Bounded backprojection and orthogonal range
    projection.  `Λ_ρ` is the Hilbert adjoint of `W_ρ : L²(ν_α) → 𝒴`:
    `⟨γ, W_ρ F⟩_{L²(λ_α)} = ⟨Λ_ρ γ, F⟩_{L²(ν_α)}`. 
  • complete
    theorem OperatorRidgelet.Paper.prop_coefficient_projection_v.{u_1}
      {H : Type u_1} [NormedAddCommGroup H] [InnerProductSpace  H]
      [CompleteSpace H] [SecondCountableTopology H] [MeasurableSpace H]
      [BorelSpace H] (ν : MeasureTheory.Measure H)
      [MeasureTheory.SigmaFinite ν] [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α) ( : OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  ) ( : OperatorRidgelet.IsAdmissible α ρ)
      (F : H  ) :
      Measurable F 
        MeasureTheory.MemLp F 2 ν 
          OperatorRidgelet.backprojection α ν ρ
              (OperatorRidgelet.spectralCoefficient ν (⇑ρ) F) =ᵐ[ν]
            fun ξ => (OperatorRidgelet.admissibilityConst α ρ) * F ξ
    theorem OperatorRidgelet.Paper.prop_coefficient_projection_v.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      (ν : MeasureTheory.Measure H)
      [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α)
      ( :
        OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ)
      (F : H  ) :
      Measurable F 
        MeasureTheory.MemLp F 2 ν 
          OperatorRidgelet.backprojection α ν
              ρ
              (OperatorRidgelet.spectralCoefficient
                    ν (⇑ρ) F) =ᵐ[ν]
            fun ξ =>
            (OperatorRidgelet.admissibilityConst
                  α ρ) *
              F ξ
    **Proposition [prop:coefficient-projection]** Bounded backprojection and orthogonal range
    projection.  `Λ_ρ W_ρ = C Id`. 
  • complete
    theorem OperatorRidgelet.Paper.prop_coefficient_projection_vi.{u_1}
      {H : Type u_1} [NormedAddCommGroup H] [InnerProductSpace  H]
      [CompleteSpace H] [SecondCountableTopology H] [MeasurableSpace H]
      [BorelSpace H] (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ] [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : } ( : 0 < α)
      ( : OperatorRidgelet.IsHomogeneous α ν) (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ)
      (γ : (MeasureTheory.Lp  2 (OperatorRidgelet.parameterMeasure ν))) :
      OperatorRidgelet.coefficientProjection α μ ν ρ γ 
          OperatorRidgelet.ridgeletRange μ ν ρ 
        γ - OperatorRidgelet.coefficientProjection α μ ν ρ γ 
          (OperatorRidgelet.ridgeletRange μ ν ρ)
    theorem OperatorRidgelet.Paper.prop_coefficient_projection_vi.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α)
      ( :
        OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ)
      (γ :
        (MeasureTheory.Lp  2
            (OperatorRidgelet.parameterMeasure
              ν))) :
      OperatorRidgelet.coefficientProjection α
            μ ν ρ γ 
          OperatorRidgelet.ridgeletRange μ ν
            ρ 
        γ -
            OperatorRidgelet.coefficientProjection
              α μ ν ρ γ 
          (OperatorRidgelet.ridgeletRange μ ν
              ρ)
    **Proposition [prop:coefficient-projection]** Bounded backprojection and orthogonal range
    projection.  `Π_ρ = C⁻¹ W_ρ P_{𝒦_α} Λ_ρ` is the orthogonal projection onto `Ran R_ρ`:
    `Π_ρ γ ∈ Ran R_ρ` and `γ - Π_ρ γ ⊥ Ran R_ρ`. 
  • complete
    theorem OperatorRidgelet.Paper.prop_coefficient_projection_vii.{u_1}
      {H : Type u_1} [NormedAddCommGroup H] [InnerProductSpace  H]
      [CompleteSpace H] [SecondCountableTopology H] [MeasurableSpace H]
      [BorelSpace H] (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ] [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : } ( : 0 < α)
      ( : OperatorRidgelet.IsHomogeneous α ν) (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ)
      (F : OperatorRidgelet.SpectralAntiDual μ ν) :
      OperatorRidgelet.synthesis μ ν (⇑ρ)
            ((OperatorRidgelet.admissibilityConst α ρ)⁻¹ 
              (OperatorRidgelet.ridgeletExtension μ ν ρ)
                (OperatorRidgelet.rieszInv μ ν F)) =
          F 
        
          (γ :
            (MeasureTheory.Lp  2 (OperatorRidgelet.parameterMeasure ν))),
          OperatorRidgelet.synthesis μ ν (⇑ρ) γ = F 
            (OperatorRidgelet.admissibilityConst α ρ)⁻¹ 
                  (OperatorRidgelet.ridgeletExtension μ ν ρ)
                    (OperatorRidgelet.rieszInv μ ν F) 
              γ
    theorem OperatorRidgelet.Paper.prop_coefficient_projection_vii.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α)
      ( :
        OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ)
      (F :
        OperatorRidgelet.SpectralAntiDual μ
          ν) :
      OperatorRidgelet.synthesis μ ν (⇑ρ)
            ((OperatorRidgelet.admissibilityConst
                    α ρ)⁻¹ 
              (OperatorRidgelet.ridgeletExtension
                  μ ν ρ)
                (OperatorRidgelet.rieszInv μ ν
                  F)) =
          F 
        
          (γ :
            (MeasureTheory.Lp  2
                (OperatorRidgelet.parameterMeasure
                  ν))),
          OperatorRidgelet.synthesis μ ν (⇑ρ)
                γ =
              F 
            (OperatorRidgelet.admissibilityConst
                        α ρ)⁻¹ 
                  (OperatorRidgelet.ridgeletExtension
                      μ ν ρ)
                    (OperatorRidgelet.rieszInv
                      μ ν F) 
              γ
    **Proposition [prop:coefficient-projection]** Bounded backprojection and orthogonal range
    projection.  The minimum-norm solution of `S_ρ γ = F ∈ 𝓔_α'` is `C⁻¹ R_ρ J_α⁻¹ F`: it solves
    the equation, and every solution has at least its norm. 
  • complete
    theorem OperatorRidgelet.Paper.prop_coefficient_projection_viii.{u_1}
      {H : Type u_1} [NormedAddCommGroup H] [InnerProductSpace  H]
      [CompleteSpace H] [SecondCountableTopology H] [MeasurableSpace H]
      [BorelSpace H] (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ] [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : } ( : 0 < α)
      ( : OperatorRidgelet.IsHomogeneous α ν) (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ)
      (F : OperatorRidgelet.SpectralAntiDual μ ν)
      (γ : (MeasureTheory.Lp  2 (OperatorRidgelet.parameterMeasure ν))) :
      OperatorRidgelet.synthesis μ ν (⇑ρ) γ = F 
        γ -
            (OperatorRidgelet.admissibilityConst α ρ)⁻¹ 
              (OperatorRidgelet.ridgeletExtension μ ν ρ)
                (OperatorRidgelet.rieszInv μ ν F) 
          (OperatorRidgelet.ridgeletRange μ ν ρ)
    theorem OperatorRidgelet.Paper.prop_coefficient_projection_viii.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α)
      ( :
        OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ)
      (F :
        OperatorRidgelet.SpectralAntiDual μ ν)
      (γ :
        (MeasureTheory.Lp  2
            (OperatorRidgelet.parameterMeasure
              ν))) :
      OperatorRidgelet.synthesis μ ν (⇑ρ) γ =
          F 
        γ -
            (OperatorRidgelet.admissibilityConst
                    α ρ)⁻¹ 
              (OperatorRidgelet.ridgeletExtension
                  μ ν ρ)
                (OperatorRidgelet.rieszInv μ ν
                  F) 
          (OperatorRidgelet.ridgeletRange μ ν
              ρ)
    **Proposition [prop:coefficient-projection]** Bounded backprojection and orthogonal range
    projection.  The solutions of `S_ρ γ = F` are exactly the coefficients that differ from the
    minimum-norm solution by an element of `(Ran R_ρ)^⊥`. 
Proof for Proposition 3.2.6
uses 0

The change of variables \xi=-\omega a gives \frac1{2\pi}\int\int|\omega|^{-\alpha}|\widehat\gamma(-\xi/\omega,\omega)|^2\mathrm d\omega\,\nu_\alpha(\mathrm d\xi)=\|\gamma\|_{\mathcal Y}^2, and weighted Cauchy–Schwarz in \omega proves absolute convergence, representative independence, the bound, and the adjoint identity. Since R_\rho=W_\rho U_\alpha with U_\alpha unitary onto \mathcal K_\alpha, C^{-1/2}W_\rho|_{\mathcal K_\alpha} is an isometry with closed image, and R_\rho'R_\rho=CJ_\alpha (the frame identity, which is the Plancherel identity read through the transpose) identifies the kernel of R_\rho' with (\operatorname{Ran}R_\rho)^\perp.

Theorem3.2.7
Statement uses 11
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L∃∀N

Let \alpha>0 and let \rho be an \alpha-admissible Schwartz filter. (i) The frame operator T_\alpha=U_\alpha'U_\alpha equals the Riesz map J_\alpha, an isometric bijection \mathcal E_\alpha\to\mathcal E_\alpha', and S_\rho R_\rho f=(\!(\rho,\rho)\!)_\alphaT_\alpha f for f\in\mathcal E_\alpha. (ii) For f\in\mathcal E_\alpha and g\in\mathcal E_\alpha', f=((\!(\rho,\rho)\!)_\alpha)^{-1}T_\alpha^{-1}S_\rho R_\rho f and g=((\!(\rho,\rho)\!)_\alpha)^{-1}S_\rho(R_\rho T_\alpha^{-1}g). (iii) If f\in\mathcal D_\alpha and \mathcal G_Qf\in L^1(\nu_\alpha), then T_\alpha f is represented by g_{\mathcal G_Qf} against \mu_Q; conversely, for G\in\mathcal K_\alpha, R_\rho T_\alpha^{-1}U_\alpha'G=W_\rho G, and when G\in L^1(\nu_\alpha), U_\alpha'G is represented by g_G and the second reconstruction formula is the spectral synthesis identity of Theorem 3.1.5 (ii). (iv) The backprojection \Lambda_\rho is a bounded operator L^2(\lambda_\alpha)\to L^2(\nu_\alpha) with \Lambda_\rho W_\rho=(\!(\rho,\rho)\!)_\alpha\mathrm{Id}, and \Lambda_\rho R_\rho f=(\!(\rho,\rho)\!)_\alphaU_\alpha f holds in L^2(\nu_\alpha) for every f\in\mathcal E_\alpha. For a concrete core input, it holds pointwise with U_\alpha f=\mathcal G_Qf when the continuous Fourier-slice representative is used. The remaining inversion step uses Gaussian input: the Hermite formula at \xi\ne0 recovers the Hermite coefficients of f from \mathcal G_Qf, these coefficients determine f in L^2(\mu_Q), and f=\Delta_Q[((\!(\rho,\rho)\!)_\alpha)^{-1}\Lambda_\rho R_\rho f].

Lean code for Theorem3.2.718 theorems
  • complete
    theorem OperatorRidgelet.Paper.thm_C_i_a.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [MeasurableSpace H]
      [BorelSpace H] (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ] [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : } ( : 0 < α)
      ( : OperatorRidgelet.IsHomogeneous α ν) (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ)
      (f : (OperatorRidgelet.spectralRange μ ν)) :
      OperatorRidgelet.frameOperator μ ν f =
        (OperatorRidgelet.rieszMap μ ν) f
    theorem OperatorRidgelet.Paper.thm_C_i_a.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α)
      ( :
        OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ)
      (f :
        (OperatorRidgelet.spectralRange μ
            ν)) :
      OperatorRidgelet.frameOperator μ ν f =
        (OperatorRidgelet.rieszMap μ ν) f
    **Theorem [thm:C]** Reconstruction and the frame operator.  The frame operator
    `T_α = U_α' U_α` equals the Riesz map `J_α`. 
  • complete
    theorem OperatorRidgelet.Paper.thm_C_i_b.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [MeasurableSpace H]
      [BorelSpace H] (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ] [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : } ( : 0 < α)
      ( : OperatorRidgelet.IsHomogeneous α ν) (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ) :
      Isometry (OperatorRidgelet.rieszMap μ ν)
    theorem OperatorRidgelet.Paper.thm_C_i_b.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α)
      ( :
        OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  )
      ( :
        OperatorRidgelet.IsAdmissible α ρ) :
      Isometry
        (OperatorRidgelet.rieszMap μ ν)
    **Theorem [thm:C]** Reconstruction and the frame operator.  The Riesz map `J_α` (hence the
    frame operator) is an isometry `𝓔_α → 𝓔_α'`. 
  • complete
    theorem OperatorRidgelet.Paper.thm_C_i_c.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [MeasurableSpace H]
      [BorelSpace H] (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ] [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : } ( : 0 < α)
      ( : OperatorRidgelet.IsHomogeneous α ν) (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ) :
      Function.Bijective (OperatorRidgelet.rieszMap μ ν)
    theorem OperatorRidgelet.Paper.thm_C_i_c.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α)
      ( :
        OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  )
      ( :
        OperatorRidgelet.IsAdmissible α ρ) :
      Function.Bijective
        (OperatorRidgelet.rieszMap μ ν)
    **Theorem [thm:C]** Reconstruction and the frame operator.  The Riesz map `J_α` (hence the
    frame operator) is a bijection `𝓔_α → 𝓔_α'`. 
  • complete
    theorem OperatorRidgelet.Paper.thm_C_i_d.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [CompleteSpace H]
      [SecondCountableTopology H] [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H) [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν] [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α) ( : OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  ) ( : OperatorRidgelet.IsAdmissible α ρ)
      (f : (OperatorRidgelet.spectralRange μ ν)) :
      OperatorRidgelet.synthesis μ ν (⇑ρ)
          ((OperatorRidgelet.ridgeletExtension μ ν ρ) f) =
        (OperatorRidgelet.admissibilityConst α ρ) 
          OperatorRidgelet.frameOperator μ ν f
    theorem OperatorRidgelet.Paper.thm_C_i_d.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α)
      ( :
        OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ)
      (f :
        (OperatorRidgelet.spectralRange μ
            ν)) :
      OperatorRidgelet.synthesis μ ν (⇑ρ)
          ((OperatorRidgelet.ridgeletExtension
              μ ν ρ)
            f) =
        (OperatorRidgelet.admissibilityConst
              α ρ) 
          OperatorRidgelet.frameOperator μ ν f
    **Theorem [thm:C]** Reconstruction and the frame operator.  The frame identity
    `S_ρ R_ρ f = C^{(α)}_ρ T_α f` for `f ∈ 𝓔_α`. 
  • complete
    theorem OperatorRidgelet.Paper.thm_C_ii_a.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [CompleteSpace H]
      [SecondCountableTopology H] [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H) [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν] [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α) ( : OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  ) ( : OperatorRidgelet.IsAdmissible α ρ)
      (f : (OperatorRidgelet.spectralRange μ ν)) :
      f =
        (OperatorRidgelet.admissibilityConst α ρ)⁻¹ 
          OperatorRidgelet.rieszInv μ ν
            (OperatorRidgelet.synthesis μ ν (⇑ρ)
              ((OperatorRidgelet.ridgeletExtension μ ν ρ) f))
    theorem OperatorRidgelet.Paper.thm_C_ii_a.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α)
      ( :
        OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ)
      (f :
        (OperatorRidgelet.spectralRange μ
            ν)) :
      f =
        (OperatorRidgelet.admissibilityConst
                α ρ)⁻¹ 
          OperatorRidgelet.rieszInv μ ν
            (OperatorRidgelet.synthesis μ ν
              (⇑ρ)
              ((OperatorRidgelet.ridgeletExtension
                  μ ν ρ)
                f))
    **Theorem [thm:C]** Reconstruction and the frame operator.  The first reconstruction
    formula `f = (C^{(α)}_ρ)⁻¹ T_α⁻¹ S_ρ R_ρ f` for `f ∈ 𝓔_α` (`T_α⁻¹ = J_α⁻¹` by part (i)). 
  • complete
    theorem OperatorRidgelet.Paper.thm_C_ii_b.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [CompleteSpace H]
      [SecondCountableTopology H] [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H) [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν] [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α) ( : OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  ) ( : OperatorRidgelet.IsAdmissible α ρ)
      (g : OperatorRidgelet.SpectralAntiDual μ ν) :
      g =
        (OperatorRidgelet.admissibilityConst α ρ)⁻¹ 
          OperatorRidgelet.synthesis μ ν (⇑ρ)
            ((OperatorRidgelet.ridgeletExtension μ ν ρ)
              (OperatorRidgelet.rieszInv μ ν g))
    theorem OperatorRidgelet.Paper.thm_C_ii_b.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α)
      ( :
        OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ)
      (g :
        OperatorRidgelet.SpectralAntiDual μ
          ν) :
      g =
        (OperatorRidgelet.admissibilityConst
                α ρ)⁻¹ 
          OperatorRidgelet.synthesis μ ν (⇑ρ)
            ((OperatorRidgelet.ridgeletExtension
                μ ν ρ)
              (OperatorRidgelet.rieszInv μ ν
                g))
    **Theorem [thm:C]** Reconstruction and the frame operator.  The second reconstruction
    formula `g = (C^{(α)}_ρ)⁻¹ S_ρ (R_ρ T_α⁻¹ g)` for `g ∈ 𝓔_α'`. 
  • complete
    theorem OperatorRidgelet.Paper.thm_C_iii_a.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [CompleteSpace H]
      [SecondCountableTopology H] [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H) [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν] [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α) ( : OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  ) ( : OperatorRidgelet.IsAdmissible α ρ)
      (f : (OperatorRidgelet.spectralCore μ ν))
      (hG :
        MeasureTheory.Integrable (OperatorRidgelet.gaussFourier μ f) ν)
      (g : (OperatorRidgelet.spectralCore μ ν)) :
      (OperatorRidgelet.frameOperator μ ν
            (OperatorRidgelet.spectralEmbed μ ν f))
          (OperatorRidgelet.spectralEmbed μ ν g) =
         (x : H),
          OperatorRidgelet.spectralTarget ν
              (OperatorRidgelet.gaussFourier μ f) x *
            (starRingEnd ) (g x) μ
    theorem OperatorRidgelet.Paper.thm_C_iii_a.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α)
      ( :
        OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ)
      (f :
        (OperatorRidgelet.spectralCore μ ν))
      (hG :
        MeasureTheory.Integrable
          (OperatorRidgelet.gaussFourier μ
            f)
          ν)
      (g :
        (OperatorRidgelet.spectralCore μ
            ν)) :
      (OperatorRidgelet.frameOperator μ ν
            (OperatorRidgelet.spectralEmbed μ
              ν f))
          (OperatorRidgelet.spectralEmbed μ ν
            g) =
         (x : H),
          OperatorRidgelet.spectralTarget ν
              (OperatorRidgelet.gaussFourier μ
                f)
              x *
            (starRingEnd ) (g x) μ
    **Theorem [thm:C]** Reconstruction and the frame operator.  If `f ∈ 𝒟_α` and
    `𝒢_Q f ∈ L¹(ν_α)`, then `T_α f` is represented by the bounded continuous function
    `g_{𝒢_Q f}`: `T_α f [g] = ∫ g_{𝒢_Q f}(x) conj(g(x)) μ_Q(dx)` for `g ∈ 𝒟_α`. 
  • complete
    theorem OperatorRidgelet.Paper.thm_C_iii_b.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [CompleteSpace H]
      [SecondCountableTopology H] [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H) [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν] [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α) ( : OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  ) ( : OperatorRidgelet.IsAdmissible α ρ)
      (G : (OperatorRidgelet.spectralRange μ ν)) :
      (OperatorRidgelet.ridgeletExtension μ ν ρ)
          (OperatorRidgelet.rieszInv μ ν
            (OperatorRidgelet.transposeEmbed μ ν G)) =
        OperatorRidgelet.spectralCoefficient ν ρ G
    theorem OperatorRidgelet.Paper.thm_C_iii_b.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α)
      ( :
        OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ)
      (G :
        (OperatorRidgelet.spectralRange μ
            ν)) :
      (OperatorRidgelet.ridgeletExtension μ ν
            ρ)
          (OperatorRidgelet.rieszInv μ ν
            (OperatorRidgelet.transposeEmbed μ
              ν G)) =
        OperatorRidgelet.spectralCoefficient ν
          ρ G
    **Theorem [thm:C]** Reconstruction and the frame operator.  Conversely, for `G ∈ 𝒦_α` the
    functional `U_α' G ∈ 𝓔_α'` satisfies `R_ρ T_α⁻¹ U_α' G = W_ρ G`. 
  • complete
    theorem OperatorRidgelet.Paper.thm_C_iii_c.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [CompleteSpace H]
      [SecondCountableTopology H] [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H) [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν] [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α) ( : OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  ) ( : OperatorRidgelet.IsAdmissible α ρ)
      (G : (OperatorRidgelet.spectralRange μ ν)) :
      MeasureTheory.Integrable (↑G) ν 
         (g : (OperatorRidgelet.spectralCore μ ν)),
          (OperatorRidgelet.transposeEmbed μ ν G)
              (OperatorRidgelet.spectralEmbed μ ν g) =
             (x : H),
              OperatorRidgelet.spectralTarget ν (↑G) x *
                (starRingEnd ) (g x) μ
    theorem OperatorRidgelet.Paper.thm_C_iii_c.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α)
      ( :
        OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ)
      (G :
        (OperatorRidgelet.spectralRange μ
            ν)) :
      MeasureTheory.Integrable (↑G) ν 
        
          (g :
            (OperatorRidgelet.spectralCore μ
                ν)),
          (OperatorRidgelet.transposeEmbed μ ν
                G)
              (OperatorRidgelet.spectralEmbed
                μ ν g) =
             (x : H),
              OperatorRidgelet.spectralTarget
                  ν (↑G) x *
                (starRingEnd ) (g x) μ
    **Theorem [thm:C]** Reconstruction and the frame operator.  When `G ∈ 𝒦_α ∩ L¹(ν_α)`, the
    functional `U_α' G` is represented by `g_G`: `U_α' G [g] = ∫ g_G(x) conj(g(x)) μ_Q(dx)` for
    `g ∈ 𝒟_α`. 
  • complete
    theorem OperatorRidgelet.Paper.thm_C_iii_d.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [CompleteSpace H]
      [SecondCountableTopology H] [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H) [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν] [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α) ( : OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  ) ( : OperatorRidgelet.IsAdmissible α ρ)
      (G : (OperatorRidgelet.spectralRange μ ν)) :
      OperatorRidgelet.transposeEmbed μ ν G =
        (OperatorRidgelet.admissibilityConst α ρ)⁻¹ 
          OperatorRidgelet.synthesis μ ν (⇑ρ)
            (OperatorRidgelet.spectralCoefficient ν ρ G)
    theorem OperatorRidgelet.Paper.thm_C_iii_d.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α)
      ( :
        OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ)
      (G :
        (OperatorRidgelet.spectralRange μ
            ν)) :
      OperatorRidgelet.transposeEmbed μ ν G =
        (OperatorRidgelet.admissibilityConst
                α ρ)⁻¹ 
          OperatorRidgelet.synthesis μ ν (⇑ρ)
            (OperatorRidgelet.spectralCoefficient
              ν ρ G)
    **Theorem [thm:C]** Reconstruction and the frame operator.  For `G ∈ 𝒦_α` the second
    reconstruction formula applied to `U_α' G` reads `U_α' G = (C^{(α)}_ρ)⁻¹ S_ρ W_ρ G`. 
  • complete
    theorem OperatorRidgelet.Paper.thm_C_iii_e.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [CompleteSpace H]
      [SecondCountableTopology H] [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H) [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν] [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α) ( : OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  ) ( : OperatorRidgelet.IsAdmissible α ρ)
      (G : (OperatorRidgelet.spectralRange μ ν)) :
      MeasureTheory.Integrable (↑G) ν 
        MeasureTheory.Integrable
            (OperatorRidgelet.coefficientFormula ρ G)
            (OperatorRidgelet.parameterMeasure ν) 
           (g : (OperatorRidgelet.spectralCore μ ν)),
            (OperatorRidgelet.transposeEmbed μ ν G)
                (OperatorRidgelet.spectralEmbed μ ν g) =
              (OperatorRidgelet.admissibilityConst α ρ)⁻¹ *
                 (x : H),
                  OperatorRidgelet.integralNetworkDensity (fun t => (ρ t))
                      (OperatorRidgelet.parameterMeasure ν)
                      (OperatorRidgelet.coefficientFormula ρ G) x *
                    (starRingEnd ) (g x) μ
    theorem OperatorRidgelet.Paper.thm_C_iii_e.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α)
      ( :
        OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ)
      (G :
        (OperatorRidgelet.spectralRange μ
            ν)) :
      MeasureTheory.Integrable (↑G) ν 
        MeasureTheory.Integrable
            (OperatorRidgelet.coefficientFormula
              ρ G)
            (OperatorRidgelet.parameterMeasure
              ν) 
          
            (g :
              (OperatorRidgelet.spectralCore
                  μ ν)),
            (OperatorRidgelet.transposeEmbed μ
                  ν G)
                (OperatorRidgelet.spectralEmbed
                  μ ν g) =
              (OperatorRidgelet.admissibilityConst
                      α ρ)⁻¹ *
                 (x : H),
                  OperatorRidgelet.integralNetworkDensity
                      (fun t => (ρ t))
                      (OperatorRidgelet.parameterMeasure
                        ν)
                      (OperatorRidgelet.coefficientFormula
                        ρ G)
                      x *
                    (starRingEnd )
                      (g x) μ
    **Theorem [thm:C]** Reconstruction and the frame operator.  When `G ∈ 𝒦_α ∩ L¹(ν_α)` and
    `γ_G ∈ L¹(λ_α)`, the second reconstruction formula for `U_α' G` is the spectral synthesis
    identity: paired with `g ∈ 𝒟_α`, `U_α' G [g] = (C^{(α)}_ρ)⁻¹ ∫ S_ρ[γ_G λ_α](x) conj(g(x)) μ_Q(dx)`
    (Lemma `lem:weak-equals-strong`). 
  • complete
    theorem OperatorRidgelet.Paper.thm_C_iv_a.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [CompleteSpace H]
      [SecondCountableTopology H] [MeasurableSpace H] [BorelSpace H]
      (ν : MeasureTheory.Measure H) [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : } ( : 0 < α)
      ( : OperatorRidgelet.IsHomogeneous α ν) (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ) :
       M,
        
          (γ :
            (MeasureTheory.Lp  2 (OperatorRidgelet.parameterMeasure ν))),
          MeasureTheory.MemLp (OperatorRidgelet.backprojection α ν ρ γ) 2
              ν 
             (ξ : H),
                OperatorRidgelet.backprojection α ν (⇑ρ) (↑γ) ξ ^ 2 ν 
              M * γ ^ 2
    theorem OperatorRidgelet.Paper.thm_C_iv_a.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      (ν : MeasureTheory.Measure H)
      [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α)
      ( :
        OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  )
      ( :
        OperatorRidgelet.IsAdmissible α ρ) :
       M,
        
          (γ :
            (MeasureTheory.Lp  2
                (OperatorRidgelet.parameterMeasure
                  ν))),
          MeasureTheory.MemLp
              (OperatorRidgelet.backprojection
                α ν ρ γ)
              2 ν 
             (ξ : H),
                OperatorRidgelet.backprojection
                      α ν (⇑ρ) (↑γ) ξ ^
                  2 ν 
              M * γ ^ 2
    **Theorem [thm:C]** Reconstruction and the frame operator.  The backprojection `Λ_ρ` is a
    bounded operator `L²(λ_α) → L²(ν_α)`: `Λ_ρ γ` is square integrable with
    `‖Λ_ρ γ‖²_{L²(ν_α)} ≤ M ‖γ‖²_{L²(λ_α)}` for a constant `M`. 
  • complete
    theorem OperatorRidgelet.Paper.thm_C_iv_b.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [CompleteSpace H]
      [SecondCountableTopology H] [MeasurableSpace H] [BorelSpace H]
      (ν : MeasureTheory.Measure H) [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : } ( : 0 < α)
      ( : OperatorRidgelet.IsHomogeneous α ν) (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ) (F : H  ) :
      Measurable F 
        MeasureTheory.MemLp F 2 ν 
          OperatorRidgelet.backprojection α ν ρ
              (OperatorRidgelet.spectralCoefficient ν (⇑ρ) F) =ᵐ[ν]
            fun ξ => (OperatorRidgelet.admissibilityConst α ρ) * F ξ
    theorem OperatorRidgelet.Paper.thm_C_iv_b.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      (ν : MeasureTheory.Measure H)
      [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α)
      ( :
        OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ)
      (F : H  ) :
      Measurable F 
        MeasureTheory.MemLp F 2 ν 
          OperatorRidgelet.backprojection α ν
              ρ
              (OperatorRidgelet.spectralCoefficient
                    ν (⇑ρ) F) =ᵐ[ν]
            fun ξ =>
            (OperatorRidgelet.admissibilityConst
                  α ρ) *
              F ξ
    **Theorem [thm:C]** Reconstruction and the frame operator.  `Λ_ρ W_ρ = C^{(α)}_ρ Id` on
    `L²(ν_α)`. 
  • complete
    theorem OperatorRidgelet.Paper.thm_C_iv_c.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [CompleteSpace H]
      [SecondCountableTopology H] [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H) [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν] [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α) ( : OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  ) ( : OperatorRidgelet.IsAdmissible α ρ)
      (f : (OperatorRidgelet.spectralCore μ ν)) (ξ : H) :
      OperatorRidgelet.backprojectionOf α (⇑ρ)
          (OperatorRidgelet.biasFourier
            (OperatorRidgelet.ridgelet μ ρ f))
          ξ =
        (OperatorRidgelet.admissibilityConst α ρ) *
          OperatorRidgelet.gaussFourier μ (↑f) ξ
    theorem OperatorRidgelet.Paper.thm_C_iv_c.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α)
      ( :
        OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ)
      (f :
        (OperatorRidgelet.spectralCore μ ν))
      (ξ : H) :
      OperatorRidgelet.backprojectionOf α (⇑ρ)
          (OperatorRidgelet.biasFourier
            (OperatorRidgelet.ridgelet μ ρ
              f))
          ξ =
        (OperatorRidgelet.admissibilityConst
              α ρ) *
          OperatorRidgelet.gaussFourier μ
            (↑f) ξ
    **Theorem [thm:C]** Reconstruction and the frame operator.  For `f ∈ 𝒟_α` the identity
    `Λ_ρ R_ρ f = C^{(α)}_ρ 𝒢_Q f` holds pointwise in `ξ`, with `Λ_ρ` computed from the continuous
    Fourier-slice representative `(a,ω) ↦ \widehat{R_ρ f}(a,ω)` of the transform. 
  • complete
    theorem OperatorRidgelet.Paper.thm_C_iv_d.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [CompleteSpace H]
      [SecondCountableTopology H] [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H) [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν] [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α) ( : OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  ) ( : OperatorRidgelet.IsAdmissible α ρ)
      {Q : H →L[] H} (hQ : OperatorRidgelet.IsTraceClassCovariance Q)
      ( : OperatorRidgelet.IsCenteredGaussian Q μ)
      (f : (OperatorRidgelet.spectralCore μ ν)) (ξ : H) :
      ξ  0 
         (n : ),
          OperatorRidgelet.hermiteCoefficient μ Q (↑f) ξ n =
            Complex.I ^ n / (inner  (Q ξ) ξ) ^ n *
              iteratedDeriv n
                (fun t => OperatorRidgelet.hermiteExtension μ Q (↑f) ξ t)
                0
    theorem OperatorRidgelet.Paper.thm_C_iv_d.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α)
      ( :
        OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ)
      {Q : H →L[] H}
      (hQ :
        OperatorRidgelet.IsTraceClassCovariance
          Q)
      ( :
        OperatorRidgelet.IsCenteredGaussian Q
          μ)
      (f :
        (OperatorRidgelet.spectralCore μ ν))
      (ξ : H) :
      ξ  0 
         (n : ),
          OperatorRidgelet.hermiteCoefficient
              μ Q (↑f) ξ n =
            Complex.I ^ n /
                (inner  (Q ξ) ξ) ^ n *
              iteratedDeriv n
                (fun t =>
                  OperatorRidgelet.hermiteExtension
                    μ Q (↑f) ξ t)
                0
    **Theorem [thm:C]** Reconstruction and the frame operator.  The Hermite inversion formula
    `E_{μ_Q}[f He_n(⟨x,ξ⟩/τ(ξ))] = i^n τ(ξ)^{-n} (d/dt)^n (e^{t²τ(ξ)²/2} 𝒢_Q f(tξ))|_{t=0}`,
    `τ(ξ) = ⟨Qξ,ξ⟩^{1/2}`, for `f ∈ 𝒟_α` and `ξ ≠ 0`. 
  • complete
    theorem OperatorRidgelet.Paper.thm_C_iv_e.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [CompleteSpace H]
      [SecondCountableTopology H] [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H) [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν] [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α) ( : OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  ) ( : OperatorRidgelet.IsAdmissible α ρ)
      {Q : H →L[] H} (hQ : OperatorRidgelet.IsTraceClassCovariance Q)
      ( : OperatorRidgelet.IsCenteredGaussian Q μ)
      (f g : (OperatorRidgelet.spectralCore μ ν)) :
      (∀ (ξ : H),
          ξ  0 
             (n : ),
              OperatorRidgelet.hermiteCoefficient μ Q (↑f) ξ n =
                OperatorRidgelet.hermiteCoefficient μ Q (↑g) ξ n) 
        f = g
    theorem OperatorRidgelet.Paper.thm_C_iv_e.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α)
      ( :
        OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ)
      {Q : H →L[] H}
      (hQ :
        OperatorRidgelet.IsTraceClassCovariance
          Q)
      ( :
        OperatorRidgelet.IsCenteredGaussian Q
          μ)
      (f g :
        (OperatorRidgelet.spectralCore μ
            ν)) :
      (∀ (ξ : H),
          ξ  0 
             (n : ),
              OperatorRidgelet.hermiteCoefficient
                  μ Q (↑f) ξ n =
                OperatorRidgelet.hermiteCoefficient
                  μ Q (↑g) ξ n) 
        f = g
    **Theorem [thm:C]** Reconstruction and the frame operator.  The Hermite coefficients over all
    `ξ ≠ 0` and `n` determine `f ∈ 𝒟_α` in `L²(μ_Q)`. 
  • complete
    theorem OperatorRidgelet.Paper.thm_C_iv_f.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [CompleteSpace H]
      [SecondCountableTopology H] [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H) [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν] [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α) ( : OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  ) ( : OperatorRidgelet.IsAdmissible α ρ)
      {Q : H →L[] H} (hQ : OperatorRidgelet.IsTraceClassCovariance Q)
      ( : OperatorRidgelet.IsCenteredGaussian Q μ)
      (f : (OperatorRidgelet.spectralCore μ ν)) :
      (OperatorRidgelet.gaussFourierInv μ ν fun ξ =>
          (OperatorRidgelet.admissibilityConst α ρ)⁻¹ *
            OperatorRidgelet.backprojectionOf α (⇑ρ)
              (OperatorRidgelet.biasFourier
                (OperatorRidgelet.ridgelet μ ρ f))
              ξ) =
        f
    theorem OperatorRidgelet.Paper.thm_C_iv_f.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      [SecondCountableTopology H]
      [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν]
      [ν.IsOpenPosMeasure] {α : }
      ( : 0 < α)
      ( :
        OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ)
      {Q : H →L[] H}
      (hQ :
        OperatorRidgelet.IsTraceClassCovariance
          Q)
      ( :
        OperatorRidgelet.IsCenteredGaussian Q
          μ)
      (f :
        (OperatorRidgelet.spectralCore μ
            ν)) :
      (OperatorRidgelet.gaussFourierInv μ ν
          fun ξ =>
          (OperatorRidgelet.admissibilityConst
                  α ρ)⁻¹ *
            OperatorRidgelet.backprojectionOf
              α (⇑ρ)
              (OperatorRidgelet.biasFourier
                (OperatorRidgelet.ridgelet μ
                  ρ f))
              ξ) =
        f
    **Theorem [thm:C]** Reconstruction and the frame operator.  Reconstruction by
    backprojection: `f = Δ_Q[(C^{(α)}_ρ)⁻¹ Λ_ρ R_ρ f]` for `f ∈ 𝒟_α`, with `Δ_Q` the inverse of
    `𝒢_Q` on its range on `𝒟_α`. 
  • complete
    theorem OperatorRidgelet.Paper.thm_C_iv_completion.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [MeasurableSpace H]
      [BorelSpace H] (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ] [MeasureTheory.SigmaFinite ν]
      {α : } ( : 0 < α) ( : OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  ) ( : OperatorRidgelet.IsAdmissible α ρ)
      (f : (OperatorRidgelet.spectralRange μ ν)) :
      OperatorRidgelet.backprojection α ν ρ
          ((OperatorRidgelet.ridgeletExtension μ ν ρ) f) =ᵐ[ν]
        fun ξ => (OperatorRidgelet.admissibilityConst α ρ) * f ξ
    theorem OperatorRidgelet.Paper.thm_C_iv_completion.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν] {α : }
      ( : 0 < α)
      ( :
        OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ)
      (f :
        (OperatorRidgelet.spectralRange μ
            ν)) :
      OperatorRidgelet.backprojection α ν ρ
          ((OperatorRidgelet.ridgeletExtension
                  μ ν ρ)
                f) =ᵐ[ν]
        fun ξ =>
        (OperatorRidgelet.admissibilityConst
              α ρ) *
          f ξ
    **Theorem [thm:C]** Backprojection after analysis recovers the completed spectral density. 
Proof for Theorem 3.2.7
uses 0

Since U_\alpha is unitary onto \mathcal K_\alpha, U_\alpha'U_\alpha f[g]=\langle U_\alpha f,U_\alpha g\rangle=\langle f,g\rangle_{\mathcal E_\alpha}, the Riesz representation theorem makes J_\alpha an isometric bijection, and the Plancherel identity gives (S_\rho R_\rho f)[g]=\langle R_\rho f,R_\rho g\rangle=(\!(\rho,\rho)\!)_\alphaJ_\alpha f[g]; (ii) follows by applying T_\alpha^{-1} or substituting f=T_\alpha^{-1}g. Part (iii) is a Fubini computation with u=J_\alpha^{-1}U_\alpha'G and Lemma 3.2.4, and (iv) first uses \Lambda_\rho W_\rho=(\!(\rho,\rho)\!)_\alpha\mathrm{Id} from Lemma 2.2.8 and R_\rho=W_\rho U_\alpha on the completion. The pointwise core formula uses the continuous Fourier-slice representative; only the final Hermite inversion invokes Lemma 3.2.5 and Gaussian input.

Corollary3.2.8
Statement uses 3
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Lemma 2.2.6
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used by 0L∃∀N

Let \rho be \alpha-admissible, put C=(\!(\rho,\rho)\!)_\alpha>0, and define D_\rho=C^{-1}T_\alpha^{-1}S_\rho. Then D_\rho R_\rho=\mathrm{Id} and \|D_\rho\|\le C^{-1/2}. If f\in\mathcal E_\alpha, \gamma_\delta\in L^2(\lambda_\alpha), and \|\gamma_\delta-R_\rho f\|_2\le\delta, then \|D_\rho\gamma_\delta-f\|_{\mathcal E_\alpha}\le\delta/\sqrt C. This is an estimate in the completion norm, not an ambient L^2(\mu_Q) or pointwise estimate.

Lean code for Corollary3.2.84 theorems
  • complete
    theorem OperatorRidgelet.Paper.cor_coefficient_stability_i.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [MeasurableSpace H]
      [BorelSpace H] (α : ) (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ] (ρ :   )
      (γ : (MeasureTheory.Lp  2 (OperatorRidgelet.parameterMeasure ν))) :
      (OperatorRidgelet.coefficientDecoder α μ ν ρ) γ =
        (↑(OperatorRidgelet.admissibilityConst α ρ))⁻¹ 
          OperatorRidgelet.rieszInv μ ν (OperatorRidgelet.synthesis μ ν ρ γ)
    theorem OperatorRidgelet.Paper.cor_coefficient_stability_i.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [MeasurableSpace H] [BorelSpace H]
      (α : ) (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      (ρ :   )
      (γ :
        (MeasureTheory.Lp  2
            (OperatorRidgelet.parameterMeasure
              ν))) :
      (OperatorRidgelet.coefficientDecoder α μ
            ν ρ)
          γ =
        (↑(OperatorRidgelet.admissibilityConst
                α ρ))⁻¹ 
          OperatorRidgelet.rieszInv μ ν
            (OperatorRidgelet.synthesis μ ν ρ
              γ)
    **Corollary [cor:coefficient-stability]** The decoder is C⁻¹ T⁻¹ S. 
  • complete
    theorem OperatorRidgelet.Paper.cor_coefficient_stability_ii.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [MeasurableSpace H]
      [BorelSpace H] (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ] [MeasureTheory.SigmaFinite ν]
      {α : } ( : OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  ) ( : OperatorRidgelet.IsAdmissible α ρ)
      (f : (OperatorRidgelet.spectralRange μ ν)) :
      (OperatorRidgelet.coefficientDecoder α μ ν ρ)
          ((OperatorRidgelet.ridgeletExtension μ ν ρ) f) =
        f
    theorem OperatorRidgelet.Paper.cor_coefficient_stability_ii.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν] {α : }
      ( :
        OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ)
      (f :
        (OperatorRidgelet.spectralRange μ
            ν)) :
      (OperatorRidgelet.coefficientDecoder α μ
            ν ρ)
          ((OperatorRidgelet.ridgeletExtension
              μ ν ρ)
            f) =
        f
    **Corollary [cor:coefficient-stability]** The bounded decoder is a left inverse. 
  • complete
    theorem OperatorRidgelet.Paper.cor_coefficient_stability_iii.{u_1}
      {H : Type u_1} [NormedAddCommGroup H] [InnerProductSpace  H]
      [MeasurableSpace H] [BorelSpace H] (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ] [MeasureTheory.SigmaFinite ν]
      {α : } ( : OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  ) ( : OperatorRidgelet.IsAdmissible α ρ) :
      OperatorRidgelet.coefficientDecoder α μ ν ρ 
        ((OperatorRidgelet.admissibilityConst α ρ))⁻¹
    theorem OperatorRidgelet.Paper.cor_coefficient_stability_iii.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν] {α : }
      ( :
        OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  )
      ( :
        OperatorRidgelet.IsAdmissible α ρ) :
      OperatorRidgelet.coefficientDecoder α μ
            ν ρ 
        ((OperatorRidgelet.admissibilityConst
              α ρ))⁻¹
    **Corollary [cor:coefficient-stability]** The decoder norm is at most 1/√C. 
  • complete
    theorem OperatorRidgelet.Paper.cor_coefficient_stability_iv.{u_1} {H : Type u_1}
      [NormedAddCommGroup H] [InnerProductSpace  H] [MeasurableSpace H]
      [BorelSpace H] (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ] [MeasureTheory.SigmaFinite ν]
      {α : } ( : OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  ) ( : OperatorRidgelet.IsAdmissible α ρ)
      (f : (OperatorRidgelet.spectralRange μ ν))
      (γ : (MeasureTheory.Lp  2 (OperatorRidgelet.parameterMeasure ν)))
      {δ : }
      ( : γ - (OperatorRidgelet.ridgeletExtension μ ν ρ) f  δ) :
      (OperatorRidgelet.coefficientDecoder α μ ν ρ) γ - f 
        δ / (OperatorRidgelet.admissibilityConst α ρ)
    theorem OperatorRidgelet.Paper.cor_coefficient_stability_iv.{u_1}
      {H : Type u_1} [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [MeasurableSpace H] [BorelSpace H]
      (μ ν : MeasureTheory.Measure H)
      [MeasureTheory.IsProbabilityMeasure μ]
      [MeasureTheory.SigmaFinite ν] {α : }
      ( :
        OperatorRidgelet.IsHomogeneous α ν)
      (ρ : SchwartzMap  )
      ( : OperatorRidgelet.IsAdmissible α ρ)
      (f :
        (OperatorRidgelet.spectralRange μ ν))
      (γ :
        (MeasureTheory.Lp  2
            (OperatorRidgelet.parameterMeasure
              ν)))
      {δ : }
      ( :
        γ -
              (OperatorRidgelet.ridgeletExtension
                  μ ν ρ)
                f 
          δ) :
      (OperatorRidgelet.coefficientDecoder α
                μ ν ρ)
              γ -
            f 
        δ /
          (OperatorRidgelet.admissibilityConst
              α ρ)
    **Corollary [cor:coefficient-stability]** Coefficient error δ gives spectral error δ/√C. 
Proof for Corollary 3.2.8
uses 0

The left-inverse identity is Theorem 3.2.7 (ii). Since the transpose S_\rho has norm at most \sqrt C and T_\alpha^{-1} is an isometry, the decoder has norm at most C^{-1}\sqrt C=C^{-1/2}. Apply this bound to \gamma_\delta-R_\rho f.