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Bochner energy under the actual reflected conditional Gibbs kernel

Kolesnikov and Milman background; Chen, Chewi, Lu and Zhang PBPS consumer; ASTIS expanded mathematical proof.

arXiv:2609.06905v1 · Appendix C.1 conditional Poincare analytic prerequisite · faithful paraphrase

Complete source statement (Samplinglib restatement)

PBPS Appendix C.1 applies a conditional Poincare inequality to the reflected conditional potential W_y(u)=V((y+u)/2)+norm(u-y)^2/(8 eta), whose lower curvature is (alpha+eta inverse)/4. The selected ASTIS prerequisite expands the missing analytic curvature route using the separately proved compact-test weighted Bochner identity: for the actual conditional law S_y, the square-generator integral equals the coordinate Hessian-square integral plus the D2W_y quadratic-form integral, and is at least (alpha+eta inverse)/4 times gradient energy. Global normalization and all tested integrability are established under the actual conditional law. This is a prerequisite expansion, not the Poincare or variance conclusion stated in C.1.

  • Paper setting: Euclidean d>=1, V C2, 0<alpha<=beta and actual Hessian bounds alpha I<=D2V<=beta I, eta>0 with beta eta<=1.
  • The Gibbs-Gaussian augmentation is (X,X+sqrt(eta)Z) with independent Gibbs X and standard Gaussian Z; S_y is the actual reflected conditional law. The Bochner prerequisite uses smooth compactly supported f; extending to the noncompact score test remains separate.

Bochner identity and curvature energy

\[\int(L_yf)^2\,dS_y=\int H_f\,dS_y+\int D^2W_y[\nabla f,\nabla f]\,dS_y\ge\frac{\alpha+\eta^{-1}}4\int\|\nabla f\|^2\,dS_y.\]

Read the formalized proofs

Each statement and proof below has its own closed Lean disclosure. Samplinglib parents, Mathlib calls and external mathematical sources are distinguished in each proof.

Samplinglib mathematical lesson

Bochner energy under the actual reflected conditional Gibbs kernel

AutoSamplingTheory.ExampleCases.ProximalBPS.ConditionalBochner.conditional_bochner_energy · theorem · Teaching coverage

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Mathematical statement

For the actual Gibbs-Gaussian augmentation there are common Markov kernels R,S: R disintegrates the swapped joint law and S_y is the reflected pushforward of R_y. Every S_y is normalized exp(-W_y) times volume, W_y(u)=V((y+u)/2)+norm(u-y)^2/(8 eta), with W_y C2 and finite strictly positive normalizer. For every smooth compactly supported f, the square of L_y f, squared gradient, coordinate Hessian-square term and genuine conditional curvature term are integrable under this same S_y. The exact normalized Bochner identity holds, and the square-generator energy bounds ((alpha+eta inverse)/4) times the gradient energy.

\[\int(L_yf)^2\,dS_y=\int H_f\,dS_y+\int D^2W_y[\nabla f,\nabla f]\,dS_y\ge\frac{\alpha+\eta^{-1}}4\int\|\nabla f\|^2\,dS_y.\]
Lean statement · conditional_bochner_energy

Common actual kernels, density and finite positive normalizer precede the universal compact-test integrability, identity and exact energy inequality.

Braces mark parameters Lean can infer; square brackets request structures such as a measurable space or probability measure. Named hypotheses are mathematical premises, not facts established by this declaration. Section parameters are described in the mathematical hypotheses above; the module link retains their exact source context.

theorem conditional_bochner_energy {E : Type*} [NormedAddCommGroup E] [InnerProductSpace ℝ E]
    [FiniteDimensional ℝ E] [MeasurableSpace E] [BorelSpace E]
    {V : E → ℝ} {α β : NNReal} {η : ℝ}
    (hα : 0 < (α:ℝ)) (hαβ : α ≤ β) (hV : ContDiff ℝ 2 V)
    (hH : ∀ x v : E, (α:ℝ)*‖v‖^2 ≤ (fderiv ℝ (fderiv ℝ V) x v) v ∧
      (fderiv ℝ (fderiv ℝ V) x v) v ≤ (β:ℝ)*‖v‖^2)
    (hη : 0 < η) (hβη : (β:ℝ)*η ≤ 1) :
    let μ := (volume : Measure E).tilted (fun x => -V x)
    let J := Measure.map (fun p : E × E => (p.1,p.1+Real.sqrt η • p.2)) (μ.prod (stdGaussian E))
    let W := fun y u : E => V ((1/2:ℝ) • (y+u)) + ‖u-y‖^2/(8*η)
    ∃ R S : Kernel E E, IsMarkovKernel R ∧ IsMarkovKernel S ∧
      (J.map Prod.swap).IsCondKernel R ∧
      (∀ y, S y = (R y).map (fun x => (2:ℝ) • x-y)) ∧
      ∀ y, S y = (volume : Measure E).tilted (fun u => -W y u) ∧
        ContDiff ℝ 2 (W y) ∧ Integrable (fun u => Real.exp (-W y u)) ∧
        0 < (∫ u, Real.exp (-W y u)) ∧
        ∀ f : E → ℝ, ContDiff ℝ ∞ f → HasCompactSupport f →
          let L := fun u => Laplacian.laplacian f u - inner ℝ (gradient (W y) u) (gradient f u)
          let H := fun u => ∑ i, ‖gradient (fun z => fderiv ℝ f z ((stdOrthonormalBasis ℝ E) i)) u‖^2
          let C := fun u => fderiv ℝ (fderiv ℝ (W y)) u (gradient f u) (gradient f u)
          Integrable (fun u => (L u)^2) (S y) ∧
          Integrable (fun u => ‖gradient f u‖^2) (S y) ∧
          Integrable H (S y) ∧ Integrable C (S y) ∧
          (∫ u, (L u)^2 ∂S y) = (∫ u, H u ∂S y) + ∫ u, C u ∂S y ∧
          (((α:ℝ)+1/η)/4) * (∫ u, ‖gradient f u‖^2 ∂S y) ≤ ∫ u, (L u)^2 ∂S y

Exact module and namespace context

Proof roadmap

  1. 1Keep one actual conditional kernel

    Use ConditionalScoreDomain to obtain common R,S, their Markov properties, disintegration and reflected pushforward. For each y it provides exactly S_y=volume tilted by -W_y, W_y C2 and the genuine lower curvature (alpha+eta inverse)/4. Do not replace S_y by an unrelated measure with an assumed curvature inequality.

  2. 2Prove the global normalizer is finite and positive

    The shared compact-test identity alone cannot prove global weight integrability. Instead, S_y is already an actual probability measure and equals the tilt. If exp(-W_y) were not integrable, Mathlib tilt would be the zero measure, contradicting S_y(univ)=1. Thus the weight is integrable. Its pointwise strict positivity and nonzero volume make Z_y strictly positive. This rules out a totalized zero-measure normalization.

  3. 3Transport the full identity and every integral domain

    Apply the actual shared Bochner theorem to W_y and f. It supplies all four weighted Integrable facts and the raw identity. The tilted-integrability equivalence transfers each fact to this same S_y. For every integrand g, the exact tilted integral equals Z_y inverse times the weighted volume integral, so multiplying the raw identity gives the normalized identity.

  4. 4Use the actual conditional curvature constant

    Apply the shared curvature-energy consequence to the inherited genuine Hessian lower bound, then multiply by positive Z_y inverse. This yields precisely (alpha+eta inverse)/4 times the S_y gradient energy. It remains a compact-test square-generator estimate. Constructing a weighted closed core/range or resolvent and extending to noncompact scores are still necessary before claiming conditional Poincare or score variance.

Full assumptions and notation

All objects and hypotheses

  • E is finite-dimensional real inner-product with Borel structure and canonical volume, including dimension zero. V:E→R is C2.
  • Alpha,beta are finite nonnegative real parameters with explicit 0<alpha≤beta and genuine alpha/beta Hessian quadratic-form bounds on V.
  • Eta>0 and beta eta≤1 are retained from the ConditionalScoreDomain parent interface. The upper scale and upper curvature restrictions are not needed by the abstract Bochner identity; they are not removed from this conditional consumer.
  • Mu is volume tilted by -V; J is the law of (X,X+sqrt(eta)Z) from independent X~mu and standard Gaussian Z. The same constructed R,S work for every y and every smooth compactly supported f.
  • No probability, conditional density, global normalizer, integrability, integration-by-parts or Poincare premise is silently added; they are derived where claimed.

Mathematical proof

1. Keep one actual conditional kernel

Use ConditionalScoreDomain to obtain common R,S, their Markov properties, disintegration and reflected pushforward. For each y it provides exactly S_y=volume tilted by -W_y, W_y C2 and the genuine lower curvature (alpha+eta inverse)/4. Do not replace S_y by an unrelated measure with an assumed curvature inequality.

\[S_y=(x\mapsto2x-y)_\#R_y=Z_y^{-1}e^{-W_y(u)}\,du.\]
Corresponding Lean step

conditional_curvature_and_score_domain supplies the same existential witnesses; the consumer retains hR,hS,hcond,hSR,hSy and hcurv.

2. Prove the global normalizer is finite and positive

The shared compact-test identity alone cannot prove global weight integrability. Instead, S_y is already an actual probability measure and equals the tilt. If exp(-W_y) were not integrable, Mathlib tilt would be the zero measure, contradicting S_y(univ)=1. Thus the weight is integrable. Its pointwise strict positivity and nonzero volume make Z_y strictly positive. This rules out a totalized zero-measure normalization.

\[0<Z_y:=\int e^{-W_y(u)}\,du<\infty.\]
Corresponding Lean step

hweight contradicts tilted_of_not_integrable using the Markov probability mass. integral_exp_pos gives hZ before any normalized inequality is transferred.

3. Transport the full identity and every integral domain

Apply the actual shared Bochner theorem to W_y and f. It supplies all four weighted Integrable facts and the raw identity. The tilted-integrability equivalence transfers each fact to this same S_y. For every integrand g, the exact tilted integral equals Z_y inverse times the weighted volume integral, so multiplying the raw identity gives the normalized identity.

\[\int g\,dS_y=Z_y^{-1}\int e^{-W_y}g,\qquad\int(L_yf)^2\,dS_y=\int H_f\,dS_y+\int C_f\,dS_y.\]
Corresponding Lean step

integrated_bochner_identity is a genuine public shared theorem call. hI uses integrable_tilted_iff only after hweight; htilt uses integral_tilted and scalar integral algebra.

4. Use the actual conditional curvature constant

Apply the shared curvature-energy consequence to the inherited genuine Hessian lower bound, then multiply by positive Z_y inverse. This yields precisely (alpha+eta inverse)/4 times the S_y gradient energy. It remains a compact-test square-generator estimate. Constructing a weighted closed core/range or resolvent and extending to noncompact scores are still necessary before claiming conditional Poincare or score variance.

\[\frac{\alpha+\eta^{-1}}4\int\|\nabla f\|^2\,dS_y\le\int(L_yf)^2\,dS_y.\]
Corresponding Lean step

The final calc applies hbound to hcurv and uses inv_nonneg.mpr hZ.le; no variance or spectral-gap theorem is assumed.

Lean verification

The exact proof begins folded immediately after the mathematical argument; the statement is folded beside the claim above.

Lean proof · conditional_bochner_energy

Reuse the genuine conditional construction and the full shared Bochner identity; derive the normalizer from actual probability and transfer all integrals exactly.

Braces mark parameters Lean can infer; square brackets request structures such as a measurable space or probability measure. Named hypotheses are mathematical premises, not facts established by this declaration. Section parameters are described in the mathematical hypotheses above; the module link retains their exact source context.

Download module (.lean)
theorem conditional_bochner_energy {E : Type*} [NormedAddCommGroup E] [InnerProductSpace ℝ E]
    [FiniteDimensional ℝ E] [MeasurableSpace E] [BorelSpace E]
    {V : E → ℝ} {α β : NNReal} {η : ℝ}
    (hα : 0 < (α:ℝ)) (hαβ : α ≤ β) (hV : ContDiff ℝ 2 V)
    (hH : ∀ x v : E, (α:ℝ)*‖v‖^2 ≤ (fderiv ℝ (fderiv ℝ V) x v) v ∧
      (fderiv ℝ (fderiv ℝ V) x v) v ≤ (β:ℝ)*‖v‖^2)
    (hη : 0 < η) (hβη : (β:ℝ)*η ≤ 1) :
    let μ := (volume : Measure E).tilted (fun x => -V x)
    let J := Measure.map (fun p : E × E => (p.1,p.1+Real.sqrt η • p.2)) (μ.prod (stdGaussian E))
    let W := fun y u : E => V ((1/2:ℝ) • (y+u)) + ‖u-y‖^2/(8*η)
    ∃ R S : Kernel E E, IsMarkovKernel R ∧ IsMarkovKernel S ∧
      (J.map Prod.swap).IsCondKernel R ∧
      (∀ y, S y = (R y).map (fun x => (2:ℝ) • x-y)) ∧
      ∀ y, S y = (volume : Measure E).tilted (fun u => -W y u) ∧
        ContDiff ℝ 2 (W y) ∧ Integrable (fun u => Real.exp (-W y u)) ∧
        0 < (∫ u, Real.exp (-W y u)) ∧
        ∀ f : E → ℝ, ContDiff ℝ ∞ f → HasCompactSupport f →
          let L := fun u => Laplacian.laplacian f u - inner ℝ (gradient (W y) u) (gradient f u)
          let H := fun u => ∑ i, ‖gradient (fun z => fderiv ℝ f z ((stdOrthonormalBasis ℝ E) i)) u‖^2
          let C := fun u => fderiv ℝ (fderiv ℝ (W y)) u (gradient f u) (gradient f u)
          Integrable (fun u => (L u)^2) (S y) ∧
          Integrable (fun u => ‖gradient f u‖^2) (S y) ∧
          Integrable H (S y) ∧ Integrable C (S y) ∧
          (∫ u, (L u)^2 ∂S y) = (∫ u, H u ∂S y) + ∫ u, C u ∂S y ∧
          (((α:ℝ)+1/η)/4) * (∫ u, ‖gradient f u‖^2 ∂S y) ≤ ∫ u, (L u)^2 ∂S y := by
  obtain ⟨R,S,hR,hS,hcond,hSR,hfiber⟩ :=
    ConditionalScoreDomain.conditional_curvature_and_score_domain hα hαβ hV hH hη hβη
  let _ : IsMarkovKernel S := hS
  dsimp only
  refine ⟨R,S,hR,hS,hcond,hSR,?_⟩
  intro y
  let W := fun u : E => V ((1/2:ℝ) • (y+u)) + ‖u-y‖^2/(8*η)
  obtain ⟨hSy,hWC,_,_,hcurv,_,_⟩ := hfiber y
  change S y = (volume : Measure E).tilted (fun u => -W u) at hSy
  have hweight : Integrable (fun u => Real.exp (-W u)) := by
    by_contra hn
    have hz : S y = 0 := hSy.trans (tilted_of_not_integrable hn)
    have hu := measure_univ (μ := S y)
    rw [hz] at hu
    norm_num at hu
  have hZ : 0 < ∫ u, Real.exp (-W u) := integral_exp_pos hweight
  refine ⟨hSy,hWC,hweight,hZ,?_⟩
  intro f hf hc
  obtain ⟨hL,hG,hHess,hC,hidentity,hbound⟩ :=
    WeightedBochner.integrated_bochner_identity W f hWC hf hc
  have hI (g : E → ℝ) (hg : Integrable (fun u => Real.exp (-W u)*g u)) :
      Integrable g (S y) := by
    rw [hSy]
    exact (integrable_tilted_iff hweight g).mpr (by simpa only [smul_eq_mul] using hg)
  have htilt (g : E → ℝ) : (∫ u, g u ∂S y) =
      (∫ u, Real.exp (-W u))⁻¹ * (∫ u, Real.exp (-W u)*g u) := by
    rw [hSy, integral_tilted]
    rw [← integral_const_mul]
    apply integral_congr_ae
    filter_upwards [] with u
    change (Real.exp (-W u) / (∫ z, Real.exp (-W z))) • g u =
      (∫ z, Real.exp (-W z))⁻¹ * (Real.exp (-W u) * g u)
    simp only [smul_eq_mul, div_eq_mul_inv]
    ring
  refine ⟨hI _ hL,hI _ hG,hI _ hHess,hI _ hC,?_,?_⟩
  · rw [htilt,htilt,htilt,hidentity,mul_add]
  · rw [htilt,htilt]
    calc
      _ = (∫ u, Real.exp (-W u))⁻¹ *
          ((((α:ℝ)+1/η)/4) * (∫ u, Real.exp (-W u)*‖gradient f u‖^2)) := by ring
      _ ≤ _ := mul_le_mul_of_nonneg_left (hbound _ hcurv) (inv_nonneg.mpr hZ.le)

end AutoSamplingTheory.ExampleCases.ProximalBPS.ConditionalBochner

Exact module and namespace context

Source assumptions versus formal assumptions

SourceActual LeanDifference kindWhy it matters
Paper setting: Euclidean d>=1, V C2, 0<alpha<=beta and actual Hessian bounds alpha I<=D2V<=beta I, eta>0 with beta eta<=1.E is finite-dimensional real inner-product with Borel structure and canonical volume, including dimension zero. V:E->R is C2.generalizationArbitrary finite-dimensional real inner-product spaces and zero dimension are allowed. The positive-dimensional Euclidean source is recovered by specialization; no full manifold result is claimed.
Appendix C.1 invokes conditional Poincare.Actual conditional Bochner identity and square-generator energy lower bound on smooth compact tests.API-limitationThis is an explicitly labeled analytic prerequisite, not proof of the source Poincare or variance conclusion.
Source strong-convexity/smoothness and step-size setting.Explicit 0<alpha<=beta, C2 V, genuine Hessian bounds and beta eta<=1 retained via ConditionalScoreDomain.sameThe Bochner argument itself needs only the lower curvature; inherited upper restrictions are disclosed as parent-interface restrictions.
Actual conditional normalized Gibbs law.One pair of common Markov R,S with disintegration and reflected pushforward, finite strictly positive normalizer, four integrability conclusions and normalized identity for every y.source-implicitProbability of the constructed S rules out the zero tilt before the exact normalized integral transfer.

Compact-test Bochner identity and curvature-energy bound only. No curvature-to-Poincare theorem, closed weighted operator/core, dense range or resolvent construction, noncompact score extension, variance estimate, macro coercivity, process/mixing/error/cost or complete-paper result.

Encoder–denoiser: accepted · domain-mismatch

Detected semantic differences

  • domains: Disclosed abstract finite-dimensional and zero-dimensional extension. — Explicitly disclosed domain extension.
  • scopes: Authored analytic prerequisite, not an explicit PBPS C.1 theorem or proof of its Poincare conclusion. — No closed generator, noncompact score extension, variance or macro coercivity; missing core/range/resolvent explicit.
  • assumptions: Inherited beta eta<=1 preserved although abstract Bochner does not need it. — Upper scale restriction retained from parent interface and distinguished from abstract Bochner needs.

A generalization is not a source correction. Proposed missing conditions require separate independent repair review. No proposed repair silently changes the original theorem.

Scope and omitted-condition boundaries
  • Compact-test Bochner identity and curvature-energy bound only. No curvature-to-Poincare theorem, closed weighted operator/core, dense range or resolvent construction, noncompact score extension, variance estimate, macro coercivity, process/mixing/error/cost or complete-paper result.
Sources, dependencies, and reuse

Source and reuse

Samplinglib parents called

Mathlib API called (external library)

  • MeasureTheory.tilted_of_not_integrable
  • MeasureTheory.integral_exp_pos
  • MeasureTheory.integrable_tilted_iff
  • MeasureTheory.integral_tilted

Mathematical sources

Samplinglib prose is not a quotation or a source-equivalence certificate. Definitions and aliases are explained as constructions, not counted as new mathematical proofs.

Which proof obligations and prerequisites are covered?

  • Independently verified prerequisite Genuine compact-test weighted Bochner identity and integrability
  • Independently verified prerequisite Actual curvature square-generator energy estimate