Published July 3, 2026 | Version 4.0

Principia Orthogona Volume Two: Contact Realization of Generative Transitions

Authors/Creators

  • 1. G6 LLC

Description

Principia Orthogona Volume Two: Contact Realization of Generative Transitions

https://totogt.github.io/geometry/vol2-contact.html

Version V4 — Deposit Edition (July 2026)

Pablo Nogueira Grossi · G6 LLC, 229 Ballantine Pkwy, Newark, NJ 07105 pablogrossi@hotmail.com · ORCID: 0009-0000-6496-2186

DOI: https://doi.org/10.5281/zenodo.21148424 (supersedes V3: 10.5281/zenodo.20755436, and V2a: 10.5281/zenodo.20159456) GitHub: github.com/TOTOGT/AXLE · AXLE Issue #13 (Gronwall asymmetry, closed in V3) Lean 4: AXLE/lean/VolumeTwo.lean

Abstract

This volume is the second in the Principia Orthogona series. Volume One developed the singularity-theoretic and variational foundations: the operator sequence C → K → F → U, the curvature threshold κ*, the Whitney A₁–A₃ singularity classification, and a symplectic preservation theorem for the fold map. The present volume constructs the explicit contact-geometric realization of those foundations. The three main results are: (A) a precise correspondence between the geometric fold operator F and the dm³ contact-Hamiltonian dissipation H_diss (§2); (B) equivalence of the curvature threshold κ* and the embodiment threshold τ (§3), with explicit values τ = 2, ε₀ = 1/3 verified in the dm³ toy model; (C) a bifurcation analysis showing that the four dm³ bifurcations correspond bijectively to the Whitney A₁–A₃ singularity types (§5).

What V4 corrects

Version V4 (July 2026) corrects a single value: the Contact Hopf bifurcation point γ* in §5.1, propagated directly from an independent audit of the companion dm³ toy model paper. No other theorem statement, canonical invariant, Lean-verified fact, or open obligation changes from V3.

Change Detail
§5.1, item (i) — Contact Hopf bifurcation Corrected γ* = e^(z₀) to γ* = 2e^(z₀). The dm³ toy model paper's V3 erratum found a spurious factor of 2 in the linearized transverse eigenvalue at the fold: the correct linearization gives λ(γ,z₀) = γe^(−z₀) − 2, not −2(1−γe^(−z₀)) = 2γe^(−z₀)−2 as stated in earlier versions. The correction is confirmed by an internal consistency check in the dm³ paper: its own baseline parameter γ=2, used throughout as the canonical case, exactly matches the corrected γ* = 2e^(z₀) at z₀=0, not the previously stated value.

What V3 added (unchanged in V4)

Certified inner-basin boundary r* = 0.77594059 (§4.7), refining the placeholder value 0.773 used in V2a. The symmetric Gronwall estimate |r−1| < 1/3 correctly bounds the outer basin, but the inner basin is asymmetric: trajectories starting at r₀ ∈ (2/3, r*) lie inside the Gronwall ball yet still escape to r → 0. The true inner boundary, certified numerically by certify_rstar.py (DOP853, rtol=1e-12, atol=1e-14, bisection tolerance 1e-7), gives the corrected hierarchy:

ε₀ = 1/3 < 2/3 < r* ≈ 0.776 < κ* = √(7/9) ≈ 0.882 < 1

AXLE Issue #13 (Gronwall asymmetry) is closed at the numerical-certificate level; the corresponding Lean obligation (thm_gronwall_asymmetry) remains open as a full formal proof (see status table below).

Lean 4 formal verification status (unchanged in V4)

All theorems have corresponding obligations in AXLE/lean/VolumeTwo.lean. Policy: no sorry is hidden — every open obligation is documented with a difficulty rating (★ = easy, ★★★★★ = frontier).

Theorem / Lemma Lean name Status
λ(0) = 0 (Prop. 4.2) eigenvalue_at_zero proved
λ(z) < 0 for z>0 (Prop. 4.2) eigenvalue_neg_pos_z proved
τ > 0 (Thm 3.2) embodimentThreshold_pos proved
τ = 2 (Prop. 4.2) toyModel_tau proved
ε₀ = 1/3 (§4.6) toyModel_epsilon0 proved
Thm C bijection (Prop. 5.1) thm_C_singularity_bijection proved
μ_max < 0 ⟺ τ > 0 thm_B_mu_iff_tau proved
A₁ surjectivity thm_C_A1_surjective proved
λ(z) → μ_max (filter) eigenvalue_limit_filter sorry ★★
Thm A (full) thm_A_contact_realization sorry ★★★★
Thm B (full chain) thm_B_full_chain sorry ★★★★★
Gronwall asymmetry thm_gronwall_asymmetry sorry ★★★ (numeric cert. V3)

Version history

Version Date Key change
V4 July 2026, DOI 10.5281/zenodo.21148424 Corrected the Contact Hopf bifurcation point γ* = e^(z₀) → 2e^(z₀) (§5.1), propagated from the dm³ toy model V3 erratum; no other change.
V3 June 2026, DOI 10.5281/zenodo.20755436 Certified inner-basin boundary r* = 0.77594059 (§4.7); AXLE Issue #13 closed; updated Lean status table; cosmetic edits.
V2a May 2026, DOI 10.5281/zenodo.20159456 Lean 4 skeleton; 7 reproducible figures; HTML dashboard; placeholder r* ≈ 0.773.

Deposit contents

principia_v4.pdf — 8-page paper (this file) principia_v4.tex — LaTeX source (XeLaTeX required; DejaVu Serif/Sans/Mono)

Build instructions

xelatex principia_v4.tex xelatex principia_v4.tex (Run twice for cross-references)

Series context

Role DOI
Series root / concept DOI 10.5281/zenodo.19117399
Volume One 10.5281/zenodo.21146416 (V6, latest)
Volume Two (this deposit) 10.5281/zenodo.21148424 (V4, latest)
Generative Contact Mechanics (companion) see companion deposit
dm³ Toy Model (companion) 10.5281/zenodo.21147306 (V3, latest)
AXLE formal verification hub github.com/TOTOGT/AXLE

MSC 2020: 37C10 (limit cycles), 53D10 (contact manifolds), 37C75 (stability), 58K05 (Whitney singularities), 37G10 (bifurcations), 70H05 (Hamiltonian systems)

Keywords: contact geometry, dm³ toy model, Whitney singularities, Gronwall stability, Lean 4 formal verification, curvature threshold, embodiment threshold, operator algebra, generative transitions, helical attractor

License: [as prior versions] Copyright: © 2026 Pablo Nogueira Grossi, G6 LLC Contact: pablogrossi@hotmail.com

Note on scope: This description reflects only what is contained in principia_v4.tex. A "Theorem T1 (Entropy monotonicity)" referenced in some prior summaries of this series does not appear in this paper; "T1" in this document refers only to a forward cross-reference to Volume IV (GTCT T1) in the G-series role table (§6.2), not to a theorem proved or stated here.

meta-author: Pablo Nogueira Grossi · G6 LLC meta-description: Volume II of Principia Orthogona. Contact-geometric realization of generative transitions. Theorems A (fold–contact correspondence), B (threshold equivalence κ*↔τ), C (singularity–bifurcation). Lean 4 formal status. G6 LLC · Pablo Nogueira Grossi · 2026. meta-viewport: width=device-width, initial-scale=1.0 title: Principia Orthogona · Volume II · Contact Realization of Generative Transitions

Principia Orthogona

← Vol I Toy Model Dashboard AXLE Zenodo Contents

Living Book Series ↗

Table of Contents

Abstract Preface 1 · Introduction 1.1 The Problem: From Folds to Dissipation 1.2 Role of the dm³ Toy Model 1.3 Main Results A · B · C 1.4 Standing Assumptions 2 · Contact Realization of the Fold 2.1 From Symplectic to Contact 2.2 The Fold as Contact Discontinuity 2.3 Contact Normal Form 2.4 Correspondence Table (Theorem A) 3 · Equivalence of κ* and τ 3.1 Geometric → Stochastic 3.2 Stochastic → Geometric 3.3 Theorem B 4 · Explicit Verification 4.3 The Exact Equations 4.4 Threshold Values 4.5 Contact Normal Form 4.6 Stability Radius ε₀ = 1/3 5 · Singularity–Bifurcation Correspondence 6 · Discussion Appendix A · Lean 4 Status References

← Volume I: Mathematics → Toy Model: SIAM Paper → Interactive Dashboard

Principia Orthogona · Volume II · Version V4 · 2026

C→ K→ F→ U

Contact Realization of Generative Transitions

Fold–contact correspondence · Threshold equivalence κ* ↔ τ · Singularity–bifurcation correspondence

Pablo Nogueira Grossi · G6 LLC · Newark, New Jersey, USA
ORCID: 0009-0000-6496-2186 · pgrossi888@outlook.com

DOI 10.5281/zenodo.21148424 Lean 4 · 8 proved 4 open sorry CC BY-NC-ND 4.0 MSC 37C10 · 53D10 · 58K05 · 37H10

Theorem A

Contact Realization of the Fold

The fold operator F is the pre-contact limit of the dm³ operator (A_{\mathrm{dm^3}}). The distributional impulse (p^+!-!p^-=\mu\mathbf{n}) corresponds to (H_{\mathrm{diss}}) in the (\beta\to\infty) limit. sorry ★★★★

Theorem B

Threshold Equivalence

(|\kappa|\uparrow\kappa^*;\Leftrightarrow;\mu_{\max}<0;\Leftrightarrow;\tau\in(0,\infty)). The curvature threshold and embodiment threshold are two names for the same event. Forward and backward directions proved (backward via companion note [11]); full formal Lean chain sorry ★★★★★

Theorem C

Singularity–Bifurcation

The four dm³ bifurcations (Hopf, saddle-node, Neimark–Sacker, slow-fast) correspond bijectively to Whitney (A_1)–(A_3) types. proved ✓

Abstract

This volume is the second in the Principia Orthogona series. Volume I developed the singularity-theoretic and variational foundations of generative transitions: the operator sequence (C \to K \to F \to U), the curvature threshold (\kappa^*), the Whitney (A_1)–(A_3) singularity classification, and a symplectic preservation theorem for the fold map. The present volume constructs the explicit contact-geometric realization of those foundations.

Three main results: (A) a precise correspondence between the geometric fold operator (F) and the dm³ contact Hamiltonian dissipation (H_{\mathrm{diss}}); (B) equivalence of the curvature threshold (\kappa^*) and the embodiment threshold (\tau), with explicit values (\tau=2), (\varepsilon_0=1/3) verified in the dm³ toy model; (C) a bifurcation analysis showing that the four dm³ bifurcations correspond bijectively to the Whitney (A_1)–(A_3) singularity types. Version V4 corrects the Contact Hopf bifurcation point in §5 (γ* = e^{z₀} → 2e^{z₀}, propagated from the dm³ toy model V3 erratum) and updates Theorem 3.4's proof to cite the companion note proving Invariant 7.5 (previously cited as an unproved invariant). Version V3 added: the certified inner-basin boundary r* = 0.77594059 (§4.7), closing AXLE Issue #13 at the numerical level. Version 2a added: Lean 4 formal proof skeleton (VolumeTwo.lean), fully-reproducible figures (figures.py, exact §4.3 equations), interactive HTML dashboard, and the Mini-Beast companion document.

Dedicated to my children Vic (R.I.P.), Giulia, Alice (R.I.P.), Sarah (R.I.P.), and David. Once tiny, always strong.

PPreface

Volume II · Contact Realization of Generative Transitions

Volume I established that generative transitions are localised geometric events classified by the Whitney (A_1)–(A_3) hierarchy. The fold operator (F) was shown to act as a symplectic canonical transformation on (T^*X), and the full transition (G = U \circ F \circ K \circ C) was shown to be a piecewise-smooth symplectic map. What Volume I deliberately left open was the question of post-fold stability: once the fold has occurred and the unfolding (U) has selected a stable branch, what governs the long-term dissipative dynamics near that branch?

The Hamiltonian framework of Volume I cannot answer this question: Liouville's theorem forbids attractors in symplectic systems on compact manifolds. The answer is contact geometry. The contact manifold (M = X \times \mathbb{R}) with contact form (\alpha = dz - \lambda) provides the correct geometric setting for dissipative dynamics with limit cycle attractors, stochastic stability, and variational structure.

The central results are: a precise correspondence between the geometric fold operator (F) and the dm³ contact Hamiltonian dissipation (§2); a theorem establishing the equivalence of the curvature threshold (\kappa^*) and the embodiment threshold (\tau) (§3); explicit verification in the dm³ toy model (§4); and a bifurcation analysis (§5). Throughout, results of Volume I, Generative Contact Mechanics, and the dm³ Toy Model paper are taken as established.

1Introduction

1.1 The Problem: From Geometric Folds to Dissipative Dynamics

Volume I established that generative transitions are classified by the Whitney (A_1)–(A_3) hierarchy. The fold operator (F) acts as a symplectic canonical transformation on (T^*X); the full transition (G = U \circ F \circ K \circ C) is a piecewise-smooth symplectic map. What Volume I left open: once the fold has occurred and (U) has selected a stable branch, what governs the long-term dissipative dynamics?

The Hamiltonian framework of Volume I cannot answer this: Liouville's theorem forbids attractors in symplectic systems on compact manifolds. The answer is contact geometry. The contact manifold (M = X \times \mathbb{R}) with contact form (\alpha = dz - \lambda), (d\lambda = \omega) provides the correct geometric setting.

1.2 Role of the dm³ Toy Model

The dm³ Toy Model [3] serves as a complete, explicit realization of the abstract contact-geometric framework and as the bridge certifying the realizability of the geometric fold theory of Volume I. The dm³ Toy Model proves that the generative transition framework is not merely definable, but fully instantiable by an explicit, smooth, globally analyzable dynamical system. Its role is logical, not empirical. See also the companion SIAM paper → and interactive dashboard →.

1.3 Main Results

SORRY ★★★★ Theorem A · Contact Realization of the Fold

The fold operator (F) of Volume I is the piecewise-smooth, pre-contact limit of the dm³ operator (A_{\mathrm{dm^3}} = \varphi^{T^*/4}) of [2]. Under the contact extension (M = X \times \mathbb{R}), the impulsive momentum jump (p^+ - p^- = \mu\mathbf{n}) at the fold corresponds to the contact Hamiltonian correction (H_{\mathrm{diss}} = -\gamma V e^{-\beta z}) in the regularized limit (\beta \to \infty).

Theorem B · Threshold Equivalence

[|\kappa|\uparrow\kappa^* ;\Longleftrightarrow; \mu_{\max} < 0 ;\Longleftrightarrow; \tau = \sqrt{c/\kappa_{\mathrm{noise}}} \in (0, \infty).]

The curvature threshold (\kappa^*) and the embodiment threshold (\tau) are two parameterizations of the same event: the onset of transverse stability in the post-fold dissipative system. Forward and backward directions both proved at the prose level (§3.3); full formal Lean chain remains open, sorry ★★★★★ (thm_B_full_chain).

PROVED ✓ Theorem C · Singularity–Bifurcation Correspondence

The four bifurcations of the dm³ toy model [3] correspond to the Whitney singularity types of Volume I under the projection (M = S \times \mathbb{R} \to S). The correspondence is bijective.

1.4 Standing Assumptions

Assumption 1.1 · Volume I Framework

The operator sequence (C \to K \to F \to U), the threshold (\kappa^*), and all results of [1] hold.

Assumption 1.2 · dm³ Framework

The dm³ system, contact manifold (M = S \times \mathbb{R}), and all results of [2, 3] hold.

2Contact Realization of the Fold Operator

2.1 From Hamiltonian Phase Space to Contact Extension

In Volume I, the fold is realized in (T^*X) as a symplectic discontinuity. At fold point (s_0):

[ p(s_0^+) - p(s_0^-) = \mu,\mathbf{n}(s_0), ]

generated by (S(\gamma) = \mu,\Theta(|\kappa(\gamma)| - \kappa^*)) ([1], §12). The fold map (\mathcal{F}: (\gamma,p) \mapsto (\gamma, p+\mu\mathbf{n})) preserves (\omega = d\gamma \wedge dp) ([1], Theorem 12.1). To capture post-fold stabilization, we pass to the contact extension (M = X \times \mathbb{R}) with (\alpha = dz - \lambda), (d\lambda = \omega) ([2], Definition 6.1).

2.2 The Fold as a Contact Discontinuity

Proposition 2.1 · Regularization of the Fold Generator

The contact dissipation (H_{\mathrm{diss}}(x,z) = -\gamma V(x)e^{-\beta z}) is a smooth regularization of (S(\gamma) = \mu,\Theta(|\kappa(\gamma)| - \kappa^)): as (\beta \to \infty) and (z \to 0^+), the correction (-\gamma \nabla V e^{-\beta z}) concentrates near (\Gamma = {V=0}) and mimics the threshold activation of (\Theta) at (\kappa = \kappa^).

Structural properties: (i) (H_{\mathrm{diss}}|\Gamma = 0); (ii) off (\Gamma): (H{\mathrm{diss}} < 0); (iii) (e^{-\beta z}) weakens dissipation as action accumulates — the orbit earns its stability.

2.3 Relation to the dm³ Contact Normal Form

By [2] (Theorem C), every dm³ system near (\Gamma) is locally contact-diffeomorphic to the normal form:

[ \dot\rho = \mu_{\max}(1 - e^{-\beta z})\rho + O(\rho^2), \quad \dot\theta = \omega + O(\rho), \quad \dot z = \omega - |\mu_{\max}|\rho^2 e^{-\beta z} + O(\rho^3). ]

2.4 Correspondence Table (proves Theorem A)

Volume I (geometric) GCM / dm³ (contact)
Curvature threshold (\kappa^*) Onset of transverse contraction
Fold impulse (p^+ - p^- = \mu\mathbf{n}) Contact correction (H_{\mathrm{diss}} = -\gamma V e^{-\beta z})
Rank-1 Jacobian loss Dissipative contact normal form
Unfolding (U) Gradient flow to (\Gamma)
Distributional generator (S) Regularized (H_{\mathrm{diss}}) (Prop. 2.1)

Theorem A is structural: the fold and the contact correction are two descriptions of the same event at different levels of regularization.

3Equivalence of κ* and τ (Theorem B)

3.1 Geometric Threshold Implies Stochastic Threshold

PROVED Lemma 3.1 · Fold activation produces hyperbolicity

If (K) drives curvature to (\kappa^*), (F) is rank-1, and (U) selects a nondegenerate branch, then (\Gamma) is hyperbolic with (\mu_{\max} < 0) and (\dot V \leq -cV) for some (c > 0).

Rank-1 loss at (F) and Morse nondegeneracy of (\Phi) yield transverse contraction. Floquet theory gives (\mu_{\max} < 0) ([1], Theorem 3.3; [2], Proposition 3.3).

PROVED Theorem 3.2 · Geometric implies stochastic threshold

Under Lemma 3.1, (\mathcal{L}V \leq -cV + \kappa_{\mathrm{noise}}|\sigma|^2) and (\tau = \sqrt{c/\kappa_{\mathrm{noise}}} \in (0,\infty)).

(\dot V \leq -cV) plus the Itô correction (\frac{1}{2}|\sigma|^2 |\mathrm{Hess},V|) gives (\mathcal{L}V \leq -cV + \kappa_{\mathrm{noise}}|\sigma|^2) with (\kappa_{\mathrm{noise}} = \frac{1}{2}\sup|\mathrm{Hess},V|). Then (\tau = \sqrt{c/\kappa_{\mathrm{noise}}} > 0) ([2], Definition 3.4).

3.2 Stochastic Threshold Implies Geometric Threshold

PROVED Lemma 3.3 · Finite τ implies transverse contraction

If (\mathcal{L}V \leq -cV + \kappa_{\mathrm{noise}}|\sigma|^2) with (c > 0), then (\mu_{\max} < 0) and (\dot V \leq -cV) near (\Gamma).

Exponential decay of (\mathbb{E}[V(X_t)]) forces (\mu_{\max} < 0) by stochastic stability theory ([2], Propositions 3.3 and 3.4).

PROVED Theorem 3.4 · Stochastic implies geometric threshold

If (\tau \in (0,\infty)), then the trajectory must have crossed (\kappa^*) and undergone a rank-1 fold.

By Lemma 3.3, (\mu_{\max} < 0), so a hyperbolic attracting cycle exists. Suppose (|\kappa| < \kappa^) everywhere. Then Corollary 1 of [11] gives: (F) acts as the identity, (\mathrm{rank}(dF) = \dim(X_C)) everywhere, no fold point exists, and the branch set is empty — no rank-1 fold and no fold-generated hyperbolic attracting cycle can occur below threshold, unconditionally. Contradiction. So (\kappa = \kappa^) must be reached.

(V4 note: this step previously cited "[1] Invariant I5," which was stated without proof in Volume I through its V5 release. It is now proved in a companion note [11], and the citation is updated to point to that note's Corollary 1, which supplies exactly this unconditional fact with no additional hypothesis.)

3.3 The Equivalence Theorem

Theorem 3.5 · Threshold Equivalence (Theorem B)

[ |\kappa|\uparrow\kappa^* ;\Longleftrightarrow; \mu_{\max} < 0 ;\Longleftrightarrow; \tau \in (0,\infty). ]

The curvature threshold (\kappa^*) is the geometric precursor of (\tau): curvature accumulation creates the conditions under which stochastic stability becomes meaningful.

Forward: Theorem 3.2. Backward: Theorem 3.4. Middle chain: (\tau > 0 \Leftrightarrow c > 0 \Leftrightarrow \mu_{\max} < 0) (Lemma 3.3). Scope: local to the fold neighbourhood and post-fold tubular neighbourhood of (\Gamma). Theorem B is now closed as a full biconditional at the prose level; the corresponding full formal Lean 4 chain (thm_B_full_chain) remains an open obligation — see AXLE VolumeTwo.lean.

Figure 2 · Theorem B — Threshold Equivalence Chain

κ* ↔ μ_max < 0 ↔ τ ∈ (0,∞)

Panel A: curvature ratio κ/κ* (normalised). Panel B: effective contraction rate μ_eff(z) = −2(1−e^{−z}) approaching μ_max = −2. Panel C: embodiment threshold τ = √(c/κ_noise); dm³ toy model: c=4, κ_noise=1, τ=2.

4Explicit Verification in the dm³ Toy Model

Theorem 4.1 · Verification of the Framework by the dm³ Toy Model

There exists an explicit smooth dynamical system on a contact manifold — the dm³ toy model — in which all of the following hold by direct computation: (1) all eight dm³ axioms satisfied simultaneously; (2) explicit contact structure (\alpha = dz - r^2 d\theta); (3) contact normal form with ((\mu_{\max}, \omega, \beta) = (-2, 1, 1)); (4) operator algebra closure; (5) stochastic stability with (\tau = 2); (6) global dynamics: attractor (\Gamma_{12}), four predicted bifurcations.

4.3 The Exact Equations

On (M = \mathbb{R}^2_{>0} \times \mathbb{R}) with polar coordinates ((r, \theta, z)) and contact form (\alpha = dz - r^2 d\theta):

[ \dot r = r(1 - r^2) + 2(r-1)e^{-z}, \qquad \dot\theta = 1, \qquad \dot z = r^2 - 2(r-1)^2 e^{-z}. \tag{4.1–4.3} ]

Limit cycle: (\Gamma = {r = 1}), period (T^* = 2\pi). The contact structure is non-degenerate: (\alpha \wedge d\alpha = -2r,dr \wedge d\theta \wedge dz \neq 0) for (r > 0).

Figure 1 · Phase Portrait — Exact dm³ Equations §4.3

RK4 integrator · exact equations 4.1–4.3

ε = 2.0

Orbits: 6

  • 12 24

λ(z) panel

Left: phase portrait — coloured curves converge to Γ = {r=1} (gold). Blue = converging; red = escaping (r < ε₀ = 1/3). Right: transverse eigenvalue λ(z) = −2(1−e^{−z}): λ(0)=0 (neutral, pre-embodiment), λ(z)<0 for z>0 (attracting).

4.4 Threshold Values

PROVED Proposition 4.2 · Explicit threshold values

(\mu_{\max} = -2), (\kappa_{\mathrm{noise}} = 1), (\tau = 2). Verified by norm_num in Lean 4.

The transverse eigenvalue (\lambda(z) = -2(1 - e^{-z})) satisfies: (\lambda(0) = 0) (neutral, pre-embodiment); (\lambda(z) < 0) for (z > 0) (attracting, post-embodiment); (\lambda(z) \to -2) as (z \to \infty) (full dm³ rate).

Linearize at (r = 1): (\dot\rho = -2(1-e^{-z})\rho + O(\rho^2)). Generator: (\mathcal{L}V = -4V(1-e^{-z}) + \sigma^2), giving (c \to 4), (\kappa_{\mathrm{noise}} = 1), (\tau = 2).

The neutral stability at (z = 0) is the mathematical content of the embodiment threshold: the orbit earns its stability by accumulating action. The crossing (z = 0 \to z > 0) corresponds exactly to the curvature crossing (\kappa \to \kappa^*) in Volume I.

4.5 Contact Normal Form

PROVED Proposition 4.3 · Contact Normal Form

In coordinates ((\rho, \theta, z)) with (\rho = r - 1), the system takes the contact normal form of [2] (Theorem C) with ((\mu_{\max}, \omega, \beta) = (-2, 1, 1)):

[ \dot\rho = -2(1-e^{-z})\rho + O(\rho^2), \quad \dot\theta = 1 + O(\rho), \quad \dot z = 1 - 2\rho^2 e^{-z} + O(\rho^3). ]

4.6 Stability Radius

PROVED Proposition 4.4 · Stability Radius ε₀ = 1/3

[ \varepsilon_0 = \frac{|\mu_{\max}|}{2(1 + \sup_\Gamma|\mathrm{Hess},V|)} = \frac{2}{2(1+2)} = \frac{1}{3}. ]

The basin asymmetry — (\varepsilon_0 = 1/3) is established for the outer basin ({r > r_{\mathrm{att}}}) only.

4.7 Inner-Basin Boundary r* (V3, AXLE Issue #13)

The symmetric Gronwall estimate (|r-1| < 1/3) correctly bounds the outer basin, but the inner basin is asymmetric: trajectories starting at (r_0 \in (2/3,, r^*)) lie inside the Gronwall ball yet still escape to (r \to 0). The true inner boundary, certified numerically by certify_rstar.py (DOP853, rtol=1e-12, atol=1e-14, bisection tolerance 1e-7), is

[ r^* = 0.77594059 ;;(\text{rounded to 3 d.p.: } 0.776). ]

The corrected hierarchy is

[ \varepsilon_0 = \tfrac{1}{3} ;<; \tfrac{2}{3} ;<; r^* \approx 0.776 ;<; \kappa^* = \sqrt{7/9} \approx 0.882 ;<; 1. ]

AXLE Issue #13 is closed at the numerical-certificate level; the corresponding Lean obligation thm_gronwall_asymmetry remains open as a full formal proof (see Appendix A).

5Singularity–Bifurcation Correspondence (Theorem C)

From [3] (Theorem C), the dm³ toy model exhibits four bifurcations: (i) contact Hopf at (\gamma = 2e^{z_0}): limit cycle loses stability, new cycle bifurcates (corrected in V4; see the dm³ toy model V3 erratum); (ii) saddle-node at (\eta \approx 0.15): two cycles collide; (iii) Neimark–Sacker at detuning (|\Delta| = \Delta^): resonant orbit loses stability, 2-torus bifurcates; (iv) slow-fast crossover at (\beta = \beta^): smooth transition between contact and classical regimes.

PROVED ✓ Proposition 5.1 · Singularity–Bifurcation Correspondence

Under projection (M = S \times \mathbb{R} \to S): (A_1) (codim 0) (\leftrightarrow) Contact Hopf + Saddle-node; (A_2) (codim 1) (\leftrightarrow) Neimark–Sacker; (A_3) (codim 2) (\leftrightarrow) Slow-fast crossover.

Higher singularities excluded: in Volume I by the Morse condition; in [2] by contact normal form rigidity (Theorem C). Proves Theorem C.

Whitney Type Codim dm³ Bifurcation Mechanism
(A_1) fold 0 Contact Hopf (H) Rank-1 loss, radial direction
(A_1) fold 0 Saddle-node (SN) Rank-1 loss, radial collision
(A_2) cusp 1 Neimark–Sacker (NS) Rank-1, 2nd angular direction
(A_3) swallowtail 2 Slow-fast crossover (SF) Rank-1, 3rd-order (z)-change

(A_1) has two dm³ preimages (both from rank-1 loss in one transverse direction). Table 2 proves Theorem C.

Figure 3 · Bifurcation Diagram — Four Bifurcation Types

γ-axis: fold depth parameter · teal = stable branch r* = 1

H = Contact Hopf (A₁), SN = Saddle-node (A₁), NS = Neimark–Sacker (A₂), SF = Slow-fast (A₃). Whitney correspondence shown at right.

6Discussion

6.1 Summary

(1) The fold operator (F) is the geometric precursor of the dm³ contact Hamiltonian (H_{\mathrm{diss}}); the distributional generator (S) is regularized by (H_{\mathrm{diss}}) in the limiting sense of Proposition 2.1 (Theorem A).

(2) (\kappa^*) and (\tau) are equivalent: each is finite and positive if and only if the other is, both detecting the onset of transverse stability (Theorem B).

(3) The four dm³ bifurcations correspond to Whitney (A_1)–(A_3) types, completing the singularity-theoretic classification of the toy model dynamics (Theorem C).

6.2 Role in the G-Series

[Not updated in this pass — table below is carried forward unchanged from V2a/V3 pending confirmation of the current book structure.]

G-Level / Volume Core Concept Fixed Point
G¹ / Vol. I Abstract Operator Algebra Orthogonal operator
G² / Vol. II (this) Contact Geometry, g₃₃ = 33 Contact fixed point
G³ / Vol. III Biological Instantiations Living form
G⁴ / Vol. IV GTCT T1, IMPA Temporal contact
G⁵ / Vol. V + AXLE Banach FPT, formal proof Complete Completeness
G⁶ / Issue 6 χ(H*(X⁶)) = 33 ∀n Open — 2026

6.3 Open Problems

Global Equivalence. Theorem B is local. A global version requires showing every (\tau)-stable dm³ system arises from a fold globally on (X).

Higher Resonances. Systematic treatment of (k:m) correspondence between higher (A_k) singularities and higher resonances.

Basin Asymmetry (AXLE Issue #13, closed in V3). The numerical certification (r^* = 0.77594059) (§4.7) establishes the inner-basin boundary. A fully formal Lean 4 proof remains open (thm_gronwall_asymmetry, ★★★).

Figure 5 · Coherence Bridge — Six Application Domains

All domains share the same contact normal form structure (Theorem 5.4 Mini-Beast)

Rows: six domains. Columns: contact normal form parameters (μ_max, ω, β, κ*). Values from Mini-Beast p. 26 (exact). Colour encodes parameter value normalised to [0,1].

ALean 4 Formal Verification Status

All theorems have corresponding obligations in AXLE/lean/VolumeTwo.lean. Policy: no sorry is hidden. Every open obligation is documented with a proof strategy and difficulty rating (★ = easy, ★★★★★ = frontier).

Theorem / Lemma Lean Name Status Notes
λ(0) = 0 (Prop. 4.2) eigenvalue_at_zero ✓ proved simp
λ(z) < 0 for z > 0 eigenvalue_neg_pos_z ✓ proved mul_neg_of_neg_of_pos
τ > 0 (Thm 3.2) embodimentThreshold_pos ✓ proved sqrt_pos_of_pos
τ = 2 (Prop. 4.2) toyModel_tau ✓ proved norm_num
ε₀ = 1/3 (§4.6) toyModel_epsilon0 ✓ proved norm_num
Thm C bijection (Prop. 5.1) thm_C_singularity_bijection ✓ proved cases on finite type
μ_max < 0 ⟺ τ > 0 thm_B_mu_iff_tau ✓ proved middle⟺right chain
A₁ surjectivity thm_C_A1_surjective ✓ proved explicit witness
λ(z) → μ_max (filter) eigenvalue_limit_filter ⚠ sorry ★★ tendsto_exp_atBot
Thm A (full) thm_A_contact_realization ⚠ sorry ★★★★ distribution theory
Thm B (full chain) thm_B_full_chain ⚠ sorry ★★★★★ Floquet + SDE
Gronwall asymmetry thm_gronwall_asymmetry ⚠ sorry ★★★ Issue #13 inner basin — numeric cert. V3

-- lambda(z) < 0 for z > 0 (PROVED — no sorry) theorem eigenvalue_neg_pos_z (sys : DM3System) (z : Real) (hz : 0 < z) : transverseEigenvalue sys z < 0 := by unfold transverseEigenvalue apply mul_neg_of_neg_of_pos sys.mu_neg have hbz : -sys.beta * z < 0 := neg_of_neg_pos (neg_pos.mpr (mul_pos sys.beta_pos hz)) linarith [Real.exp_lt_one_of_neg hbz]

Full source: github.com/TOTOGT/AXLE · lean/VolumeTwo.lean

References

  1. [1]P. Nogueira Grossi, Principia Orthogona, Volume I: The Mathematics of Generative Transitions, G6 LLC, 2026. vol1-mathematics.html · Zenodo 21146416 (V6, latest — updated from 19117400)
  2. [2]P. Nogueira Grossi, Generative Contact Mechanics, submitted to J. Geom. Mech., 2026. Zenodo 19122168 (DOI not independently re-verified in this pass — flag if incorrect)
  3. [3]P. Nogueira Grossi, The dm³ Operator: Explicit Toy Model and Global Dynamical Analysis, submitted to SIAM J. Appl. Dyn. Syst., 2026. vol2-toymodel.html · Zenodo 21147306 (V3, latest — updated from 20230624)
  4. [4]V.I. Arnold, Mathematical Methods of Classical Mechanics, 2nd ed. Springer, 1989.
  5. [5]A. Bravetti, Contact Hamiltonian mechanics, Ann. Phys. 376 (2017), 17–39.
  6. [6]M. de León and M. Lainz Valcázar, Contact Hamiltonian systems, J. Math. Phys. 60 (2019), 102902.
  7. [7]J. Guckenheimer and P. Holmes, Nonlinear Oscillations, Dynamical Systems, and Bifurcations of Vector Fields, Springer, 1983.
  8. [8]M.W. Hirsch, C.C. Pugh, and M. Shub, Invariant Manifolds, Lecture Notes in Mathematics 583, Springer, 1977.
  9. [9]R.Z. Has'minskiǐ, Stochastic Stability of Differential Equations, Sijthoff and Noordhoff, 1980.
  10. [10]P. Nogueira Grossi, AXLE: Lean 4 Formal Verification Engine. github.com/TOTOGT/AXLE (2026).
  11. [11]P. Nogueira Grossi, Injectivity Before Threshold: Proof of Invariant 7.5, companion note to Principia Orthogona Volume I, 2026.

Acknowledgments. The author acknowledges with gratitude the foundational influence of the teachings of Paramahamsa Nithyananda and the yogic scriptural tradition from which this work derives.

Continue the Series

The toy model SIAM paper proves four theorems (A–D) with full global dynamical analysis. The interactive dashboard provides live exploration of all dm³ figures.

Toy Model Paper → Interactive Dashboard → ← Volume I

Principia Orthogona · Volume I · Toy Model · Dashboard · AXLE · Zenodo 21148424

© 2026 Pablo Nogueira Grossi / G6 LLC · Newark, New Jersey, USA
ORCID: 0009-0000-6496-2186 · pgrossi888@outlook.com · DOI 10.5281/zenodo.21148424 · CC BY-NC-ND 4.0 · MSC 37C10 · 53D10

G6 LLC · g6llc@proton.me · +1 (646) 342-3751

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Additional details

Related works

Cites
Preprint: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=6439626 (URL)
Is documented by
Software: https://www.github.com/TOTOGT/AXLE (URL)
Is part of
Preprint: 10.5281/zenodo.19117399 (DOI)
Is supplement to
Preprint: 10.5281/zenodo.19117399 (DOI)

Software

Repository URL
https://www.github.com/TOTOGT/AXLE
Programming language
Python , Lean
Development Status
Active

References

  • [1] P. Nogueira Grossi, Principia Orthogona, Volume One: The Mathematics of Generative Transitions, preprint, HAL, 2026. [2] P. Nogueira Grossi, Generative Contact Mechanics: A Geometric Framework for Dissipative Systems with Structured Limit Cycles, submitted to J. Geom. Mech., 2026.
  • [2] P. Nogueira Grossi, Generative Contact Mechanics: A Geometric Framework for Dissipative Systems with Structured Limit Cycles, submitted to J. Geom. Mech., 2026.
  • [3] P. Nogueira Grossi, The dm3 Operator: Explicit Toy Model and Global Dynamical Analysis, submitted to SIAM J. Appl. Dyn. Syst., 2026.
  • [4] V. I. Arnold, Mathematical Methods of Classical Mechanics, 2nd ed., Springer, New York, 1989.
  • [5] A. Bravetti, Contact Hamiltonian mechanics, Ann. Phys. 376 (2017), 17–39.
  • [6] M. de Le´on and M. Lainz Valc´azar, Contact Hamiltonian systems, J. Math. Phys. 60 (2019), 102902.
  • [7] J. Guckenheimer and P. Holmes, Nonlinear Oscillations, Dynamical Systems, and Bifurcations of Vector Fields, Springer, New York, 1983.
  • [8] M. W. Hirsch, C. C. Pugh, and M. Shub, Invariant Manifolds, Lecture Notes in Mathematics 583, Springer, Berlin, 1977.
  • [9] R. Z. Has'mi˘nski˘ı, Stochastic Stability of Differential Equations, Sijthoff & Noordhoff, 1980.
  • [10] M. Shub, Global Stability of Dynamical Systems, Springer, New York, 1987.