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Corrected Poincaré–Treshchev persistence under almost-periodic perturbations

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KAMMainCorrected.poincareTreshchevPersistence

by ShouqiaoWang · Aug 26, 2026 · Mathlib c5ea003 (Lean v4.30.0)

almost-periodic-functionsdynamical-systemshamiltonian-systemsinvariant-torikam-theorysmall-divisorssymplectic-geometry

Let n,mn,mn,m be positive natural numbers and put d=n+md=n+md=n+m. Let g⊂Zdg\subset\mathbb Z^dg⊂Zd be a primitive rank-mmm subgroup equipped with a matrix K0=(K1,K2)∈Mat⁡d×d(Z)K_0=(K_1,K_2)\in\operatorname{Mat}_{d\times d}(\mathbb Z)K0​=(K1​,K2​)∈Matd×d​(Z) of determinant 111, whose last mmm columns generate ggg and whose first nnn columns form the complementary block. Let G⊂RdG\subset\mathbb R^dG⊂Rd be bounded and closed, let N:Rd→RN:\mathbb R^d\to\mathbb RN:Rd→R be real analytic on a neighborhood of GGG, and let ω=(ωj)j∈Z\omega=(\omega_j)_{j\in\mathbb Z}ω=(ωj​)j∈Z​ be a real external frequency vector.

Let S\mathcal SS be a covering spatial structure of finite subsets of Z\mathbb ZZ, with exponent ϱ>2\varrho>2ϱ>2 and shell weight

[A]=1+∑j∈Alog⁡ϱ(1+∣j∣).[A]=1+\sum_{j\in A}\log^{\varrho}(1+|j|).[A]=1+j∈A∑​logϱ(1+∣j∣).

For a finitely supported integer mode kkk, call it admissible when supp⁡k⊂A\operatorname{supp}k\subset Asuppk⊂A for some A∈SA\in\mathcal SA∈S, and let [[k]][[k]][[k]] be the minimum [A][A][A] among such shells. Let Δ:[0,∞)→[1,∞)\Delta:[0,\infty)\to[1,\infty)Δ:[0,∞)→[1,∞) be nondecreasing, satisfy Δ(0)=1\Delta(0)=1Δ(0)=1, have log⁡Δ(t)/t\log\Delta(t)/tlogΔ(t)/t nonincreasing on (0,∞)(0,\infty)(0,∞) and tending to 000 at infinity, and satisfy ∫0∞log⁡Δ(t)t−2 dt<∞\int_0^\infty\log\Delta(t)t^{-2}\,dt<\infty∫0∞​logΔ(t)t−2dt<∞. Assume that a constant γ>0\gamma>0γ>0 gives

∣∑j∈Zkjωj∣≥γΔ([[k]])Δ(∑j∣kj∣)\left|\sum_{j\in\mathbb Z}k_j\omega_j\right| \ge\frac{\gamma}{\Delta([[k]])\Delta(\sum_j|k_j|)}​j∈Z∑​kj​ωj​​≥Δ([[k]])Δ(∑j​∣kj​∣)γ​

for every nonzero admissible mode kkk.

Let P(θ,x,y,ϵ)P(\theta,x,y,\epsilon)P(θ,x,y,ϵ) be the real perturbation specified by shell-indexed Fourier coefficients PA,k,k~,ℓ(y,ϵ)P_{A,k,\widetilde k,\ell}(y,\epsilon)PA,k,k,ℓ​(y,ϵ), where A∈SA\in\mathcal SA∈S, kkk is an admissible external mode, k~∈Zn\widetilde k\in\mathbb Z^nk∈Zn, and ℓ∈Zm\ell\in\mathbb Z^mℓ∈Zm. Assume the coefficients are holomorphic on one complex neighborhood of G×[−1,1]G\times[-1,1]G×[−1,1], obey the reality symmetry, define the actual Fourier sum, and admit nonnegative bounds BAB_ABA​ and positive widths r,sr,sr,s such that

∣PA,k,k~,ℓ(y,ϵ)∣er(∣k∣1+∣k~∣1+∣ℓ∣1)≤BA,∑ABAes[A]<∞.|P_{A,k,\widetilde k,\ell}(y,\epsilon)| e^{r(|k|_1+|\widetilde k|_1+|\ell|_1)}\le B_A, \qquad \sum_A B_Ae^{s[A]}<\infty.∣PA,k,k,ℓ​(y,ϵ)∣er(∣k∣1​+∣k∣1​+∣ℓ∣1​)≤BA​,A∑​BA​es[A]<∞.

Define the internal frequency ∇N(y)\nabla N(y)∇N(y) by the Fréchet derivative of NNN, and set

O(g,G)={y∈G:K2T∇N(y)=0},Ω(y)=K1T∇N(y).O(g,G)=\{y\in G:K_2^{\mathsf T}\nabla N(y)=0\}, \qquad \Omega(y)=K_1^{\mathsf T}\nabla N(y).O(g,G)={y∈G:K2T​∇N(y)=0},Ω(y)=K1T​∇N(y).

In the adapted angles (ψ,ϕ)=K0Tx(\psi,\phi)=K_0^{\mathsf T}x(ψ,ϕ)=K0T​x, let h0(ϕ,y)h_0(\phi,y)h0​(ϕ,y) be the zero external and zero ψ\psiψ Fourier coefficient of PPP at ϵ=0\epsilon=0ϵ=0. Write

O0={y∈O(g,G):∃ϕ∈Tm, ∇ϕh0(ϕ,y)=0, det⁡Dϕ2h0(ϕ,y)≠0},Ω0=Ω(O0).O_0=\left\{y\in O(g,G):\exists\phi\in\mathbb T^m, \ \nabla_\phi h_0(\phi,y)=0, \ \det D_\phi^2h_0(\phi,y)\ne0\right\}, \qquad \Omega_0=\Omega(O_0).O0​={y∈O(g,G):∃ϕ∈Tm, ∇ϕ​h0​(ϕ,y)=0, detDϕ2​h0​(ϕ,y)=0},Ω0​=Ω(O0​).

Assume O0O_0O0​ is nonempty. Assume there is ξ∗>0\xi_*>0ξ∗​>0 such that, for every 0<ξ≤ξ∗0<\xi\le\xi_*0<ξ≤ξ∗​, the sets

Ωξ={η∈Ω0:ξ≤dist⁡(η,∂Ω0)},Oξ={y∈O0:Ω(y)∈Ωξ}\Omega_\xi=\{\eta\in\Omega_0:\xi\le\operatorname{dist}(\eta,\partial\Omega_0)\}, \qquad O_\xi=\{y\in O_0:\Omega(y)\in\Omega_\xi\}Ωξ​={η∈Ω0​:ξ≤dist(η,∂Ω0​)},Oξ​={y∈O0​:Ω(y)∈Ωξ​}

have the following properties: OξO_\xiOξ​ is measurable and compact; Ωξ\Omega_\xiΩξ​ has positive nnn-dimensional Lebesgue measure; D(∇N)(y)D(\nabla N)(y)D(∇N)(y) is injective for every y∈Oξy\in O_\xiy∈Oξ​; Ω:Oξ→Ωξ\Omega:O_\xi\to\Omega_\xiΩ:Oξ​→Ωξ​ is an analytic bijection with analytic inverse and a constant cξ>0c_\xi>0cξ​>0 satisfying cξ∣y−y′∣≤∣Ω(y)−Ω(y′)∣c_\xi|y-y'|\le|\Omega(y)-\Omega(y')|cξ​∣y−y′∣≤∣Ω(y)−Ω(y′)∣; and every critical point ϕ\phiϕ of h0(⋅,y)h_0(\cdot,y)h0​(⋅,y) for y∈Oξy\in O_\xiy∈Oξ​ has nonzero Hessian determinant.

For the suspended Hamiltonian on (TZ×ℓ1(Z;R))×(Td×Rd)(\mathbb T^{\mathbb Z}\times\ell^1(\mathbb Z;\mathbb R))\times(\mathbb T^d\times\mathbb R^d)(TZ×ℓ1(Z;R))×(Td×Rd),

Hϵ(θ,J,x,y)=∑j∈ZωjJj+N(y)+ϵP(θ,x,y,ϵ),\mathcal H_\epsilon(\theta,J,x,y)= \sum_{j\in\mathbb Z}\omega_jJ_j+N(y)+\epsilon P(\theta,x,y,\epsilon),Hϵ​(θ,J,x,y)=j∈Z∑​ωj​Jj​+N(y)+ϵP(θ,x,y,ϵ),

the following holds. For every 0<ξ≤ξ∗0<\xi\le\xi_*0<ξ≤ξ∗​ there exist ϵ0∈(0,1]\epsilon_0\in(0,1]ϵ0​∈(0,1], a function c:(0,ϵ0]→[0,∞)c:(0,\epsilon_0]\to[0,\infty)c:(0,ϵ0​]→[0,∞) with c(ϵ)→0c(\epsilon)\to0c(ϵ)→0 as ϵ↓0\epsilon\downarrow0ϵ↓0, and sets Λϵ⊂Rd\Lambda_\epsilon\subset\mathbb R^dΛϵ​⊂Rd such that, for every 0<ϵ≤ϵ00<\epsilon\le\epsilon_00<ϵ≤ϵ0​:

  1. Λϵ\Lambda_\epsilonΛϵ​ is closed, measurable, nonempty, and contained in OξO_\xiOξ​.

  2. The excluded reduced-frequency volume tends to zero:

vol⁡n(Ω(Oξ∖Λϵ))⟶0(ϵ↓0).\operatorname{vol}_n\bigl(\Omega(O_\xi\setminus\Lambda_\epsilon)\bigr) \longrightarrow0\qquad(\epsilon\downarrow0).voln​(Ω(Oξ​∖Λϵ​))⟶0(ϵ↓0).
  1. For every y∈Λϵy\in\Lambda_\epsilony∈Λϵ​ and every ϕ∈Tm\phi\in\mathbb T^mϕ∈Tm satisfying ∇ϕh0(ϕ,y)=0\nabla_\phi h_0(\phi,y)=0∇ϕ​h0​(ϕ,y)=0 and det⁡Dϕ2h0(ϕ,y)≠0\det D_\phi^2h_0(\phi,y)\ne0detDϕ2​h0​(ϕ,y)=0, there is a topological embedding
ι:TZ×Tn⟶(TZ×ℓ1)×(Td×Rd).\iota:\mathbb T^{\mathbb Z}\times\mathbb T^n \longrightarrow (\mathbb T^{\mathbb Z}\times\ell^1)\times (\mathbb T^d\times\mathbb R^d).ι:TZ×Tn⟶(TZ×ℓ1)×(Td×Rd).

Every coordinate of ι\iotaι has an actual shell-indexed analytic almost-periodic Fourier expansion, and its external-action component has one uniformly controlled weighted-ℓ1\ell^1ℓ1-valued expansion. The map ι\iotaι is the image of the standard embedding

ι0(θ,ψ)=((θ,0),(K0−T(ψ,ϕ),y))\iota_0(\theta,\psi)= \bigl((\theta,0),(K_0^{-\mathsf T}(\psi,\phi),y)\bigr)ι0​(θ,ψ)=((θ,0),(K0−T​(ψ,ϕ),y))

under a local homeomorphism between open suspended-phase neighborhoods that fixes θ\thetaθ, is differentiable in all canonical cylinder directions, and preserves ∑jdθj∧dJj+∑idxi∧dyi\sum_jd\theta_j\wedge dJ_j+\sum_i dx_i\wedge dy_i∑j​dθj​∧dJj​+∑i​dxi​∧dyi​ on those directions.

Along the rigid translation with frequency (ω,Ω(y))(\omega,\Omega(y))(ω,Ω(y)), every coordinate solves the actual canonical Hamilton equation:

ddtι(q+t(ω,Ω(y)))=XHϵ ⁣(ι(q+t(ω,Ω(y)))).\frac d{dt}\iota\bigl(q+t(\omega,\Omega(y))\bigr) =X_{\mathcal H_\epsilon}\!\left( \iota\bigl(q+t(\omega,\Omega(y))\bigr)\right).dtd​ι(q+t(ω,Ω(y)))=XHϵ​​(ι(q+t(ω,Ω(y)))).

The external pairing is convergent and the external action velocity belongs to ℓ1\ell^1ℓ1 along this torus. Finally, for every torus point, every external and internal angle coordinate is within c(ϵ)c(\epsilon)c(ϵ) of ι0\iota_0ι0​, the ℓ1\ell^1ℓ1 norm of the external action is at most c(ϵ)c(\epsilon)c(ϵ), and every internal action coordinate is within c(ϵ)c(\epsilon)c(ϵ) of yyy.

This is a corrected formal version of Theorem 2.7: the full twist and reduced-frequency diffeomorphism are explicit hypotheses rather than consequences hidden in the notation.

Formalization Note The parameter sets called “Cantor sets” in the paper are required here to be closed, measurable, nonempty, and asymptotically full in reduced-frequency volume; perfectness and total disconnectedness are not asserted. External-angle tangent directions are finitely supported, while external-action tangent directions range over all of ℓ1\ell^1ℓ1.

Preamble
import Definitions.Def_frame_2026_kam_interfaces
Formal statement
noncomputable section

namespace KAMMainCorrected

open Filter MeasureTheory Set
open scoped Topology
open KAMInterfaces

variable {n m : ℕ}

theorem poincareTreshchevPersistence (M : Model n m) :
    PoincareTreshchevPersistenceProblem M := by sorry

end KAMMainCorrected
Source
Yuan Zhang, Wen Si, and Jianguo Si, Poincaré–Treshchev Mechanism in Integrable Hamiltonian Systems Under Almost-Periodic Perturbations, Discrete and Continuous Dynamical Systems 52 (2026), 32–69, Theorem 2.7 on journal p. 39, with Definitions 2.2–2.4, equations (5)–(7), and the full twist/parameter reduction used in Lemma 3.2 on pp. 41–43: https://doi.org/10.3934/dcds.2026043
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What the Lean code literally says, in plain math · gpt-5.6-sol

Theorems.KAMMainCorrected / KAMMainCorrected.poincareTreshchevPersistence

For every n,m∈Nn,m\in\mathbb Nn,m∈N and every model MMM of those dimensions, the theorem asserts the following. Here a model consists of an integer unimodular resonance frame K0K_0K0​ whose last mmm columns generate a specified resonance subgroup, a parameter set G⊆Rn+mG\subseteq\mathbb R^{n+m}G⊆Rn+m, a real function N:G-ambient→RN:G\text{-ambient}\to\mathbb RN:G-ambient→R, an arbitrary external frequency family ω:Z→R\omega:\mathbb Z\to\mathbb Rω:Z→R, shell-indexed complex Fourier coefficients PA,k,ℓ,r(y,ϵ)P_{A,k,\ell,r}(y,\epsilon)PA,k,ℓ,r​(y,ϵ), an approximation function Δ\DeltaΔ, a real divisor constant γ\gammaγ, and a spatial structure SSS. The assertion is universal over every possible proof package hhh satisfying all of these conditions:

  • n>0n>0n>0 and m>0m>0m>0; the resonance subgroup is primitive; GGG is closed and bounded; and NNN is real analytic on a neighborhood of GGG.
  • Writing ∇N\nabla N∇N for the coordinate Fréchet derivative, K2K_2K2​ for the last mmm columns of K0K_0K0​, and K1K_1K1​ for the first nnn, the set of y∈Gy\in Gy∈G such that K2T∇N(y)=0K_2^T\nabla N(y)=0K2T​∇N(y)=0 and for which there exists a circle angle ϕ∈Tm\phi\in\mathbb T^mϕ∈Tm satisfying
∇ϕh0(ϕ,y)=0,det⁡Dϕ(∇ϕh0)(ϕ,y)≠0\nabla_\phi h_0(\phi,y)=0,\qquad \det D_\phi(\nabla_\phi h_0)(\phi,y)\ne0∇ϕ​h0​(ϕ,y)=0,detDϕ​(∇ϕ​h0​)(ϕ,y)=0

is nonempty. The averaged function here is the explicit real Fourier sum

h0(ϕ,y)=Re⁡∑A,rPA,0,0,r(y,0)ei⟨r,ϕ~⟩,h_0(\phi,y)=\operatorname{Re}\sum_{A,r} P_{A,0,0,r}(y,0)e^{i\langle r,\widetilde\phi\rangle},h0​(ϕ,y)=ReA,r∑​PA,0,0,r​(y,0)ei⟨r,ϕ​⟩,

evaluated at the standard real representative ϕ~\widetilde\phiϕ​ of the circle angle.

  • The package supplies r∗>0r_*>0r∗​>0. For every 0<ξ≤r∗0<\xi\le r_*0<ξ≤r∗​, form the reduced-frequency image
O=K1T∇N({y∈G:K2T∇N(y)=0 and some associated nondegenerate ϕ exists}),\mathcal O=K_1^T\nabla N\bigl(\{y\in G:K_2^T\nabla N(y)=0 \text{ and some associated nondegenerate }\phi\text{ exists}\}\bigr),O=K1T​∇N({y∈G:K2T​∇N(y)=0 and some associated nondegenerate ϕ exists}),

retain those Ω∈O\Omega\in\mathcal OΩ∈O with

ξ≤infDist⁡(Ω,frontier⁡O),\xi\le\operatorname{infDist}(\Omega,\operatorname{frontier}\mathcal O),ξ≤infDist(Ω,frontierO),

and pull this trim back to the preceding resonant set. That pulled-back set is measurable and compact, while the reduced trim has strictly positive nnn-dimensional Lebesgue volume. At every retained yyy, the full derivative D(∇N)(y):Rn+m→Rn+mD(\nabla N)(y):\mathbb R^{n+m}\to\mathbb R^{n+m}D(∇N)(y):Rn+m→Rn+m is injective. The map y↦K1T∇N(y)y\mapsto K_1^T\nabla N(y)y↦K1T​∇N(y) is analytic near the pulled-back trim, maps it bijectively onto the reduced trim, has an analytic two-sided inverse on those sets, and admits one lower Lipschitz constant τ>0\tau>0τ>0 on the source. Every ϕ\phiϕ that is averaged-critical at every retained yyy, not only one chosen critical point, has nonzero averaged Hessian determinant.

  • The divisor constant satisfies γ>0\gamma>0γ>0, and every nonzero finitely supported integer mode kkk whose support lies in an allowed spatial shell obeys
∣⟨k,ω⟩∣≥γΔ([k]S)Δ(∣k∣1).|\langle k,\omega\rangle| \ge \frac{\gamma}{\Delta([k]_S)\Delta(|k|_1)}.∣⟨k,ω⟩∣≥Δ([k]S​)Δ(∣k∣1​)γ​.

The spatial structure covers every integer site, so all unit modes occur in this quantifier.

  • There exist positive angular, spatial, and complex-parameter widths and nonnegative shell bounds BAB_ABA​, zero off the allowed spatial shells, with ∑ABAes[A]S\sum_A B_Ae^{s[A]_S}∑A​BA​es[A]S​ summable. Coefficients vanish unless their external support lies in their indexing allowed shell, are complex differentiable on the corresponding complex neighborhoods of GGG and [−1,1][-1,1][−1,1], and satisfy the uniform exponential Fourier bound ∣PA,μ∣ea∣μ∣1≤BA|P_{A,\mu}|e^{a|\mu|_1}\le B_A∣PA,μ​∣ea∣μ∣1​≤BA​. Each shell’s coefficient norms are summable; coefficients satisfy conjugate symmetry on real G×[−1,1]G\times[-1,1]G×[−1,1]; the actually summed perturbation is real analytic in all lifted finite angle, parameter, and perturbation variables for every real external lift; and the actually summed averaged potential above is analytic near Rm×G\mathbb R^m\times GRm×G.

For every such package hhh and every real 0<ξ≤r∗0<\xi\le r_*0<ξ≤r∗​, there must exist ϵ0∈R\epsilon_0\in\mathbb Rϵ0​∈R with 0<ϵ0≤10<\epsilon_0\le10<ϵ0​≤1, a function r:R→Rr:\mathbb R\to\mathbb Rr:R→R, and a family of parameter sets Λϵ⊆Rn+m\Lambda_\epsilon\subseteq\mathbb R^{n+m}Λϵ​⊆Rn+m satisfying the following. The rate obeys r(ϵ)≥0r(\epsilon)\ge0r(ϵ)≥0 for every 0<ϵ≤ϵ00<\epsilon\le\epsilon_00<ϵ≤ϵ0​ and tends to 000 as ϵ→0\epsilon\to0ϵ→0 through positive values. For every such ϵ\epsilonϵ, Λϵ\Lambda_\epsilonΛϵ​ is closed in the ambient space, measurable, nonempty, and contained in the ξ\xiξ-trimmed nondegenerate resonant set. Moreover,

vol⁡n ⁣((K1T∇N)(trim⁡ξ(M)∖Λϵ))⟶0as ϵ→0+.\operatorname{vol}_n\!\left( (K_1^T\nabla N)\bigl( \operatorname{trim}_\xi(M)\setminus\Lambda_\epsilon \bigr)\right)\longrightarrow0 \quad\text{as }\epsilon\to0^+.voln​((K1T​∇N)(trimξ​(M)∖Λϵ​))⟶0as ϵ→0+.

This is the volume of the reduced-frequency image of the removed parameter set, not the ambient (n+m)(n+m)(n+m)-dimensional volume of that set; the statement gives only the limit, not a pointwise quantitative estimate for each ϵ\epsilonϵ.

For every 0<ϵ≤ϵ00<\epsilon\le\epsilon_00<ϵ≤ϵ0​, every y∈Λϵy\in\Lambda_\epsilony∈Λϵ​, and every ϕ∈Tm\phi\in\mathbb T^mϕ∈Tm, if the explicit averaged gradient at (ϕ,y)(\phi,y)(ϕ,y) is zero and its explicit Hessian determinant is nonzero, then there exists a map

ι:(TZ×Tn)⟶((TZ×ℓR1)×(Tn+m×Rn+m))\iota:\bigl(\mathbb T^{\mathbb Z}\times\mathbb T^n\bigr) \longrightarrow \bigl((\mathbb T^{\mathbb Z}\times\ell^1_{\mathbb R}) \times(\mathbb T^{n+m}\times\mathbb R^{n+m})\bigr)ι:(TZ×Tn)⟶((TZ×ℓR1​)×(Tn+m×Rn+m))

with all of these properties:

  • ι\iotaι is a topological embedding.
  • There exist widths a,s,wa,s,wa,s,w with a>0a>0a>0, s>0s>0s>0, and 0≤w<s0\le w<s0≤w<s such that every external-angle circle coordinate, every finite-angle circle coordinate, and every finite action coordinate has an actual shell-indexed Fourier expansion with external and internal characters, allowed-shell support, absolute mode summability, bounds ∣cA,μ∣ea∣μ∣1≤BA|c_{A,\mu}|e^{a|\mu|_1}\le B_A∣cA,μ​∣ea∣μ∣1​≤BA​, and spatially weighted shell-bound summability. The full external ℓ1\ell^1ℓ1-action component has one complex ℓ1\ell^1ℓ1-valued expansion whose coefficients and output are summable with weight ew[j]Se^{w[j]_S}ew[j]S​, whose weighted norms are globally summable over shell modes, and whose Banach-valued Fourier series converges pointwise to the complexification of the real output.
  • Let the standard torus be
ι0(θ,ψ)=((θ,0),(K0−T(ψ,ϕ),y)),\iota_0(\theta,\psi)= ((\theta,0),(K_0^{-T}(\psi,\phi),y)),ι0​(θ,ψ)=((θ,0),(K0−T​(ψ,ϕ),y)),

where the code uses the integer adjugate formula. There exists a local coordinate transformation FFF between open subsets of suspended phase space, with continuous two-sided inverse on those subsets, whose source contains the whole range of ι0\iota_0ι0​, which fixes every external angle, and for which ι=F∘ι0\iota=F\circ\iota_0ι=F∘ι0​. For every source point and every two cylinder directions—directions with finitely supported external-angle part, arbitrary ℓ1\ell^1ℓ1 external-action part, and arbitrary finite components—the relevant coordinate curves of FFF are differentiable, the external series of the two output tangents is summable, and

∑j(dθj∧dJj)+∑i(dxi∧dyi)\sum_j(d\theta_j\wedge dJ_j)+\sum_i(dx_i\wedge dy_i)j∑​(dθj​∧dJj​)+i∑​(dxi​∧dyi​)

has the same value on the output tangents as on the input directions.

  • Put Ω=K1T∇N(y)\Omega=K_1^T\nabla N(y)Ω=K1T​∇N(y) and translate the source torus rigidly by (ω,Ω)(\omega,\Omega)(ω,Ω). At every source point qqq and every time ttt, with z=ι(Ttq)z=\iota(T_tq)z=ι(Tt​q), the external pairing ∑jωjJj\sum_j\omega_jJ_j∑j​ωj​Jj​ is summable, the raw external action velocity belongs to ℓ1\ell^1ℓ1, every one-coordinate external-angle derivative of the Hamiltonian exists, and the lifted Hamiltonian is differentiable in all finite action and angle variables at zzz. Every external-angle circle coordinate of s↦ι(Tsq)s\mapsto\iota(T_sq)s↦ι(Ts​q), its full external-action component, every finite-angle circle coordinate, and its finite-action component has derivative at s=ts=ts=t equal to the corresponding component of the explicit Hamiltonian vector field of
Hϵ(θ,J,x,y)=∑jωjJj+N(y)+ϵP(θ,x,y,ϵ).\mathcal H_\epsilon(\theta,J,x,y) =\sum_j\omega_jJ_j+N(y)+\epsilon P(\theta,x,y,\epsilon).Hϵ​(θ,J,x,y)=j∑​ωj​Jj​+N(y)+ϵP(θ,x,y,ϵ).

Thus invariance is pointwise in every coordinate and for all q,tq,tq,t, rather than almost everywhere.

  • For every torus point qqq, every external output angle lies within r(ϵ)r(\epsilon)r(ϵ) of qqq’s external angle; the norm of the full external-action output is at most r(ϵ)r(\epsilon)r(ϵ); every finite output angle lies within r(ϵ)r(\epsilon)r(ϵ) of the corresponding angle of K0−T(qint,ϕ)K_0^{-T}(q_{\rm int},\phi)K0−T​(qint​,ϕ); and every finite output action coordinate differs from yyy by at most r(ϵ)r(\epsilon)r(ϵ).

The threshold, rate, and family Λ\LambdaΛ may depend on MMM, the entire hypothesis witness, and ξ\xiξ; the embedding may further depend on ϵ,y,ϕ\epsilon,y,\phiϵ,y,ϕ. Each retained yyy belongs to the nondegenerate resonant set and therefore has at least one associated nondegenerate ϕ\phiϕ, so the embedding implication cannot be false-premised for every ϕ\phiϕ at that yyy. Nothing is asserted at ϵ=0\epsilon=0ϵ=0, for negative ϵ\epsilonϵ, or above ϵ0\epsilon_0ϵ0​. The theorem takes an arbitrary model and concludes a proposition universally quantified over CorrectedHypotheses witnesses; consequently, if no such witness exists for MMM, the theorem is vacuously true for that model. If a witness does exist, its positive trim radius ensures that the subsequent ξ\xiξ-quantifier has admissible values.

Human review
  • Endorsed by Shuze Chen · Aug 27, 2026

  • Endorsed by ShouqiaoWang · Aug 27, 2026

    Confirmed by the mission captain (proposal self-audit).

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