Update Incompatibility in Discrete Black-Hole Interiors: Three-Domain Separation, Orbit Dichotomy, and the Bridge Gap in Radial-Potential Lifting
离散黑洞内区的更新不相容:三域分离、轨道二岔,与径向势提升之桥缺口
Discretising the black-hole interior is widely expected to dissolve classical geodesic incompleteness. The expectation is rarely examined in point of form. What the trapped region delivers is a statement about worldlines and events: every future-directed causal direction strictly decreases the areal radius. What a discrete occupancy model delivers is a statement about configurations: which occupancy patterns may follow which. Between the two there must be a bridge.
This paper separates three objects that are routinely conflated, takes as primitive a labelled transition system whose configuration graph is a quotient, and shows that the bridge is not an automatic consequence of those premises. The witness is the ring shift: in a saturated region, a closed chain in which every cell simultaneously sends one unit and receives one is number-conserving, involves only nearest neighbours, requires no vacancy, and leaves the occupancy function unchanged. The projection from transitions to configurations can therefore fail to be faithful.
The main theorem has four parts. Every maximal orbit of a finite deterministic configuration dynamics either terminates in finitely many steps or is eventually periodic. If a bounded-below potential descends by a uniform amount along every transition, the periodic branch is excluded and orbits terminate within a computable bound; this part requires neither finiteness nor determinism. Forward totality and uniform strict descent cannot coexist. And under radial non-increase, every transition on a cycle has zero potential change. Taken together: in a finite deterministic configuration dynamics, an infinite orbit that never repeats a configuration is unavailable, though events may still never repeat.
Three bridges are distinguished and ordered, with both converses failing. The main theorem requires the weakest of them that still does work, and the radial potential is a sufficient special case rather than a necessity. Nine numbered refutations are recorded in three groups, the first two forming a squeeze. Two applications follow: exact recurrence is incompatible with persistent positive net outflow on the same cycle, and a local exclusion lemma together with an influence-cone envelope whose volume fraction has leading term 3⟨h⟩t/R under local finite-speed updating.
Both answers to the bridge question carry a cost. If the bridge is not delivered, a model's pure occupancy dynamics cannot by itself claim to carry the inwardness of the trapped region. If it is delivered, forward totality is lost on the spot.
This paper claims no material core, no interior layer state, no resolution of the singularity, and no observational projection. What it offers is an auditing framework: anyone proposing to carry the trapped region's inwardness by way of a finite, forward-complete discrete occupancy dynamics must state explicitly how the bridge is crossed.
Keywords: discrete black-hole interior; trapped region; forward completeness; radial potential; type separation; no-go theorem
Conventions and notation
The refutation convention follows the SAE ZFCρ series [33], §10. Within this paper refutations are written Kill n; when cited across series the domain is supplied by the citing work, as ZFCρ Kill 17 or BH Kill 3. Paper 1 of the present series [31], §3.7, writes K0 through K5 and G1, G2 for its preregistered criteria and supporting diagnostics; these are similar in appearance and different in kind, and on first mention are written in full as "the preregistered criterion K3 of Paper 1."
Where this paper revises or corrects earlier work, the citation is given to the section and proposition, not to the DOI alone.
Commitment levels, bridge statuses and refutation sources are collected in the status map of §8. Individual sections do not carry their own level markings.
1 Introduction
1.1 The problem
Classical gravity predicts geodesic incompleteness in the black-hole interior. Many approaches to quantum gravity replace continuum spacetime with a discrete substrate [1,2], and the expectation that commonly accompanies them is this: given a minimum scale, collapse cannot proceed to a singularity, so incompleteness resolves itself.
The form of that expectation is rarely examined. Models that support a regular core with an effective stress tensor [3–7], and models in which a minimum scale produces a bounce [8], share it. Once a discrete model has been written down, one observes that it has a minimum length and concludes that the singularity is avoided. But the conclusion requires two steps: that the model can carry the dynamics of the trapped region at all, and that this dynamics does not, at the discrete level, lead to termination. Neither is self-evident, and the first is the one that is usually skipped.
The defining property of the trapped region, in the standard theory, is a statement about worldlines and events: every future-directed causal direction strictly decreases the areal radius. What a discrete occupancy model describes is a transition between configurations: which occupancy distribution may follow which. These do not live on the same level. Passing from the first to the second requires a bridge.
That bridge is the subject of this paper.
1.2 The gap
The content the bridge must supply can be made precise. Let the occupancy configuration be n, and let the radial potential be Φ(n) = Σ n_x r(x). If the inwardness of the trapped region lifts to the configuration level, then every update strictly decreases Φ.
That lifting requires every occurrence to change the configuration, and the requirement generally fails. The counterexample is the ring shift: a closed chain in a saturated region in which every cell simultaneously sends one unit and receives one, conserving number and leaving the occupancy function everywhere unchanged (Lemma 3.9).
> Motion of worldlines and events does not entail change of occupancy configuration.
The construction itself is not new: a conserving closed-chain permutation is a familiar object in lattice gases and exclusion processes [24,25]. What is new here is its use as a witness for the failure of that entailment, that is, as a witness for type separation.
1.3 What this paper does
Three-domain separation. The spatial cell graph, the configuration transition graph, and the occurrence unfolding are distinguished, and a type-checking rule is imposed: a cycle, or the absence of one, in any one domain may not stand in for a conclusion about another without an explicit bridge. The occurrence unfolding serves as a semantic convention rather than a third primitive dynamics; its cost is that configuration periodicity can no longer be used to argue for the absence of time, and that cost is what shows the convention is not free.
A main theorem. Orbit dichotomy and radial-potential obstruction, in four parts (§4). The parts do not share a premise level: the first requires finiteness and determinism and yields recurrence; the second requires neither and yields termination. Stated as separate theorems this asymmetry is invisible; combined, it shows.
Exposure of the bridge. From the ring shift and the two timing conventions, the bridge is shown to fail on either side, and to succeed only under a third convention at the cost of forward totality. This is the paper's central opening and its only physical remainder.
Nine refutations. Numbered and grouped by function following the convention of [33], §10. The first group is over-inheritance from the continuum, the second over-inference from discreteness; together they squeeze a narrow corridor. The third is mutual incompatibility.
Two applications. Exact recurrence against persistent positive net outflow; a local exclusion lemma and an influence-cone bound.
1.4 The nature of this paper, and its limits
The mathematics here is elementary: a quantity bounded below cannot descend uniformly without end, and a finite deterministic system must return. None of what is specific to black holes lies in that piece of combinatorics. It lies in the bridge. The contribution is therefore not depth of mathematics but minimisation of dependence and audit of type. What is delivered is a framework for auditing discrete-interior models, not a verdict on what the interior of a black hole is.
Its jurisdiction accordingly extends to any model that would carry the trapped region by way of a finite discrete occupancy dynamics, and is not confined to the present framework.
This paper claims no material core, no interior layer state, and no numerical value for an occupancy or density bound. It does not claim to resolve the singularity: abandoning forward totality yields orbit termination, and naming is not dissolving — no proof is offered that such a terminal state is equivalent to a classical singularity. It offers no observational projection. It does not claim a derivation of Hawking radiation. It does not treat Kerr.
1.5 Organisation
Section 2 refutes a common inference, that the degeneration of the lapse at the horizon entails the absence of a global time direction in the interior, and gives a trichotomy of criteria. Section 3 establishes the three-domain separation and the ring shift. Section 4 states the main theorem. Section 5 combines the two into the bridge gap and gives an exit matrix. Section 6 gives two applications. Section 7 discusses the bridges not yet built, this paper's refutations, and the minimal entry point for what follows. Section 8 is the status map. Appendix A carries the continuum spherical-symmetry no-go and the reason it does not suffice to establish discrete same-shell acyclicity. Appendix B carries the numerics, the closed form of the lattice coefficient, and the hashes of the code.
1.6 Dependency matrix
Only conditions actually used by the theorems of this paper are listed. Anything that enters no proof is omitted.
| Condition | Role | Status |
|---|---|---|
| K is a complete and autonomous microstate space | prevents hidden variables from changing the future | unbuilt bridge |
| U is forward-total | the core of forward completeness | to be established |
| Φ is bounded below | condition for potential obstruction | conditional assumption |
| all allowed transitions descend uniformly | the bridge from continuum inwardness to configurations | unbuilt bridge |
| projection from events to configurations is non-identity | written H_occ | generally false |
| the complete state has no outward output | condition for recurrence | conflicts with the inherited broadcast statement |
| local finite propagation speed | condition for the influence cone | model assumption |
| the three clauses of Model 4.10 | exhaustiveness of the cycle support | model assumption |
The framework's posits concerning a core — the origin of an occupancy bound, the map between an internal ledger and the boundary mass, matching conditions, and stability — enter no theorem here and are therefore not listed. Since this paper claims no core, enumerating the full burden of a future core paper would serve only completeness and would add nothing to its conclusions.
Commitment levels, bridge statuses and refutation sources are collected in §8 and are not tabulated here, so that the two cannot fall out of step.
2 Lapse does not yield a category
2.1 The inference to be refuted, and its provenance
> (F) dτ/dt → 0 at r = r_s ⟹ the interior has no global time direction.
What this section corrects is a route previously taken within the present framework. The existing articulation of the interior is Info-4 [9], §4.4, which rests on the asymptotic divergence of the tick interval at the horizon. That section already declares three things: the result is a finite-time consequence rather than an absolute claim that time does not exist; it is an outside-observer reading conditional on a finite lifetime bound, marked Layer 2, a conditional structural reading, in that paper's §11; and the internal-observer perspective is placed under Layer 5 strict silence.
So (F) is not merely unsupported by its upstream. It is excluded by that upstream's own declaration: a statement constructed to say what an outside observer can conclude within finite time does not produce an internal categorical fact.
This is an instance of retrospective correction under recursive subdivision. Subdivision of the physical-quantity ladder [32] separates what previously shared a rung, and the earlier coarse-grained articulation must be revised accordingly.
2.2 A type error
dτ/dt is a lapse. It gives proper time per unit coordinate time; it is a rate. Whether a global time direction exists is a categorical or topological property of the causal structure. That the rate of evolution vanishes in one direction does not entail that the direction is undefinable or unorientable.
2.3 A counterexample
Proposition 2.1. The trapped region of Schwarzschild is time-orientable.
Proof. Take ingoing Eddington–Finkelstein coordinates [10,11],
ds² = −f dv² + 2 dv dr + r² dΩ², f = 1 − r_s/r,
which are regular across the horizon. Let
X = ∂_v − (1 + f²) ∂_r.
From g_vv = −f, g_vr = 1 and g_rr = 0,
g(X,X) = −f − 2(1 + f²) = −(2f² + f + 2) = −[2(f + ¼)² + 15/8] ≤ −15/8 < 0
for every real f. Moreover X^v ≡ 1 is nowhere zero. Hence X is a continuous, nowhere-vanishing timelike vector field on the ingoing region r > 0, and that region is time-orientable. ∎
Remark 2.2. The future orientation of X agrees with the ingoing EF family, so its orientation is not an arbitrary choice.
Remark 2.3 (the status of the antecedent). It is sometimes said that the antecedent of (F) is simply a coordinate artefact. That is too strong, and four layers should be distinguished. First, the Schwarzschild t coordinate does fail at the horizon, and this is a matter of coordinates. Second, the expression dτ/dt = √f applies only to static worldlines at fixed r in the exterior; inside the horizon there are no static timelike observers at fixed r, so that ratio does not carry its original operational meaning there. Third, the static Killing field becomes null at the Killing horizon, and the vanishing of its norm is a geometric fact, not a coordinate product. Fourth, redshift relative to a static clock at infinity has operational meaning as well.
What may therefore be asserted is this: the numerical value of the Schwarzschild lapse depends on the static slicing and on the normalisation of Killing time, and its vanishing cannot by itself carry the coordinate-independent conclusion that time-orientability is lost. This denies neither the physical content of exterior static redshift nor the geometric significance of that vanishing.
2.4 Criteria: two failed routes and one surviving candidate
To mark a categorical transition at the horizon by some quantity, the quantity must reach its mark at r_s for every mass, and must not be a rate-like structure.
First, local strength scalars: failed. The Kretschmann scalar of the Schwarzschild solution [12] is K = 12r_s²/r⁶ [13–15], so
K(r_s) = 12/r_s⁴ = 3c⁸/4G⁴M⁴,
which becomes arbitrarily small as the mass grows. Hence among the local strength scalars considered, none attains a fixed threshold at r_s for arbitrary mass; criteria defined by curvature, density or tidal force do not coincide with r_s.
Second, the lapse: failed. The square of the Schwarzschild static lapse — equivalently the norm of the static Killing vector — degenerates at r_s for every mass, but it is a rate and a static-observer structure and yields no categorical conclusion. It should be named as such, and not written as a general coordinate-independent scalar.
Third, marginal trappedness: surviving. In this clause geometric units G = c = 1 are used, so r_s = 2M. Under spherical symmetry the Misner–Sharp quasi-local mass [16] m(r) is defined by 1 − 2m(r)/r = g^ab ∂_a r ∂_b r, and
2m(r)/r = 1 ⟺ ∇r is null ⟺ the surface is marginally trapped.
For Schwarzschild m(r) ≡ M, so the condition holds exactly at r = 2M = r_s. This criterion is coordinate-independent and quasi-local, and under spherical symmetry it is the same object as a marginally trapped surface [17]; no fourth category is required.
The limit of the survivor. Marginal trappedness may mark a phase region, but without an additional update theorem it cannot by itself deliver forward completeness. And it should be noted that in static Schwarzschild r_s is a marginal trapped surface, whereas the classical singularity theorems [18] use closed trapped surfaces among their hypotheses [19]; the two are related and must not be written as identical.
2.5 The causal direction in the interior
Proposition 2.4. In the trapped region, every future-directed causal direction strictly decreases r.
Proof. In ingoing EF coordinates a causal vector V satisfies
g(V,V) = −f(V^v)² + 2V^v V^r + r²|V_Ω|² ≤ 0.
The angular term r²|V_Ω|² is non-negative, so −f(V^v)² + 2V^v V^r ≤ 0. For r < r_s we have f < 0. Two branches.
First, V^v > 0. Then 2V^v V^r ≤ f(V^v)² ≤ 0, so V^v V^r ≤ 0 and V^r ≤ 0. If V^r = 0 then g(V,V) = −f(V^v)² + r²|V_Ω|² ≥ −f(V^v)² > 0, contradicting causality; hence V^r < 0 strictly.
Second, V^v = 0. This branch exists in ingoing EF coordinates: it is the radial null direction. Here g(V,V) = r²|V_Ω|², and causality requires this to be non-positive, so V_Ω = 0 and V ∝ ∂_r with g(V,V) = 0. Orientation is fixed by the field X of Proposition 2.1: g(∂_r, X) = g_rv = 1 > 0, so ∂_r is past-directed and the future-directed choice has V^r < 0.
Both branches give V^r < 0. ∎
This proposition is the left end of the bridge of §5.2. What it constrains is the direction of worldlines and events, not the descent of configurations; the difference between the two is the entire content of §3 and §5.
3 Three-domain separation
3.1 Three domains and their primitive objects
An argument about a discrete interior must distinguish three objects. Conflating them is the primary misinference this paper is designed to prevent.
Definition 3.1 (spatial cell graph). Let V_cell be a finite set of cells and E_adj a symmetric, irreflexive adjacency relation. Write G_sp = (V_cell, E_adj).
Definition 3.2 (configuration space). With occupancy bound n_max,
𝒳 = { n : V_cell → {0, 1, …, n_max} }.
Definition 3.3 (labelled transition system). The primitive dynamical object of this paper is the five-tuple
𝒯 = (𝒳, Θ, s, t, M),
where Θ is a set of transitions, s, t : Θ → 𝒳 give source and target, and
M(θ) = { x_i ⇝ y_i }_{i ∈ I(θ)}
is the multiset of atomic transports carried by that transition, with x_i and y_i adjacent. The target is determined by the source together with the transports:
t(θ)(z) = s(θ)(z) − #{i : x_i = z} + #{i : y_i = z}.
Legality requires 0 ≤ t(θ)(z) ≤ n_max everywhere. Write θ_idle for a transition with M(θ_idle) = ∅.
Definition 3.4 (the configuration graph as a quotient).
G_cfg = (𝒳, E_U), E_U = { (s(θ), t(θ)) : θ ∈ Θ }.
The configuration graph is not primitive; it is a quotient of 𝒯. Distinct transitions may give the same edge of E_U.
Definition 3.5 (occurrence unfolding). Fix an initial configuration n₀. Let ℰ be the set of finite composable transition strings θ₁θ₂⋯θ_k issuing from n₀, ordered by proper prefix and written ≺, and let
π : ℰ → 𝒳
send a string to the configuration it reaches. Write G_evt = (ℰ, ≺).
What is used here is the standard labelled-transition history unfolding. It shares with the event-structure and occurrence-net tradition [20,21] a single discipline, namely the distinction between the type of a transition and its occurrence; but the full concurrency partial order is not needed here. To be precise: the elements of ℰ are histories, not single events, and Θ is a set of transition labels rather than occurrences themselves.
Three domains, not four. Space, configuration and occurrence remain three. 𝒯 is not a fourth domain; it is the primitive structure that gives the latter two their objects, the configuration graph by quotient and the occurrence unfolding by strings.
3.2 The type-checking rule
Principle 3.6. A cycle, or the absence of one, in any one domain may not stand in for a conclusion about another without an explicit bridge.
The rule is most often violated in the passage from motion to change. So a bridge is named:
Definition 3.7.
H_occ : ∀θ ∈ Θ, s(θ) ≠ t(θ).
That is: every transition projects to a non-identity change of configuration. The next subsection shows it generally fails.
Remark 3.8. This is sharper than a formulation in terms of consecutive occurrences, which would require the string structure to define adjacency. Since transitions are themselves objects, the condition can be stated directly.
3.3 Non-faithfulness of the projection
Lemma 3.9 (ring shift). Let B ⊆ V_cell be saturated and let x₁, …, x_k (k ≥ 3) be a closed chain in B. Let θ_↻ ∈ Θ have
M(θ_↻) = { x₁ ⇝ x₂, x₂ ⇝ x₃, …, x_k ⇝ x₁ }.
Then the transition conserves number, involves only nearest neighbours, requires no vacancy, and
M(θ_↻) ≠ ∅, s(θ_↻) = t(θ_↻).
Proof. Each cell of the chain sends one and receives one, so t(θ)(z) = s(θ)(z) − 1 + 1 = s(θ)(z) on the chain, and cells off the chain are untouched. Legality follows from 0 ≤ n_max ≤ n_max. ∎
Corollary 3.10. H_occ generally fails.
> There exists θ ∈ Θ with M(θ) ≠ ∅ and s(θ) = t(θ).
Remark 3.11 (an ontological limit, to be stated). If the particles are wholly indistinguishable and the complete physical state is nothing but the occupancy function, then "the particles really went around" is not a fact recognisable within that model. So what the lemma asserts is not that a pure occupancy state secretly contains observable worldlines. It asserts:
> Projection from a finer transition dynamics onto occupancy configurations may fail to be faithful.
This is weaker than the loose formulation and more accurate, and it is exactly what the argument needs: the main theorem acts on a potential over configurations, and descent of that potential must be delivered by transitions; a non-trivial transition does not guarantee a change of configuration, let alone a descent.
Remark 3.12 (a discipline of wording). Wherever "identity edge" appears it refers to identity of the configuration projection and does not assert M(θ) = ∅. That distinction is the whole content of Lemma 3.9.
3.4 Timing conventions
Convention 3.13. Any discussion of occupancy updates must first declare its timing, since what Θ contains depends on it.
Sequential single hop. |M(θ)| ≤ 1, and when |M(θ)| = 1 the source must be occupied and the target must have room. Under this convention the ring shift does not belong to Θ.
Synchronous exchange. M(θ) may carry several transports applied simultaneously, and legality requires only that the resulting configuration lie within bounds everywhere. Under this convention the ring shift belongs to Θ; and by the open chain of §5.3, a saturated interior may also be traversed.
Remark 3.14. These are not the whole space of timings but two minimal representative realisations. Random parallel updating, block synchrony and finite-depth local circuits are further realisations; this paper does not treat them and does not claim to have exhausted the space.
3.5 Four classes of state
If updating is restricted to a deterministic partial function, states fall into four classes: update-terminal, fixed configuration, transient active, and non-trivially periodic. These four names are used directly; no separate indicator functions are introduced.
4 Orbit dichotomy and radial-potential obstruction
The theorem of this section absorbs six results previously stated separately: the change of the occupancy potential, the dichotomy between termination and periodicity, the step bound, the incompatibility with forward totality, the vanishing of potential change around a cycle, and the obstruction of directed cycles by strict radial monotonicity. Once combined, the layering of their premises becomes visible: the first part needs finiteness and determinism, the second needs neither. Stated separately, that asymmetry cannot be seen.
4.1 The occupancy potential
Definition 4.1. Let r : V_cell → ℝ give the radial coordinate of a cell. Define
Φ(n) = Σ_x n_x r(x).
Lemma 4.2. For a single atomic transport moving one unit from x to y,
ΔΦ = r(y) − r(x).
Proof. Direct substitution. ∎
A strictly inward transport decreases Φ; a same-shell transport leaves it unchanged. On a finite lattice the strictly inward edges have a minimum drop
δ_min = min{ r(x) − r(y) : x ∼ y, r(y) < r(x) }.
When the set of allowed strictly inward edges is non-empty, finiteness of the lattice gives δ_min > 0; if that set is empty there are no strictly inward transports and what follows does not apply.
4.2 The main theorem
Theorem 4.3. The theorem is stated in two settings, so that formal objects are not mixed.
General transition setting. Let 𝒯 = (K, Θ, s, t) be a labelled transition system. Parts B through D hold in this setting.
Finite deterministic special case. If configuration successors are unique, so that the configuration quotient of 𝒯 induces a deterministic partial function U : K ⇀ K, and |K| < ∞, then Part A holds as well. Write U(x)↓ to say that U is defined at x.
Part A (orbit dichotomy). Every maximal orbit has exactly one of two ends: it terminates in finitely many steps, or it is eventually periodic. If U is forward-total the terminating branch is excluded, so every orbit is eventually periodic.
Part B (uniform descent obstruction). Suppose there is Φ : K → ℝ with inf_K Φ > −∞ and a uniform constant δ > 0 such that every transition θ ∈ Θ satisfies Φ(t(θ)) ≤ Φ(s(θ)) − δ. Then every forward path issuing from x₀ has length at most
N_max = ⌊ (Φ(x₀) − inf_K Φ) / δ ⌋,
so the periodic branch is excluded and no infinite forward path exists.
Part C (incompatibility). Seriality and bounded-below uniform strict descent cannot coexist:
[∀x ∃θ : s(θ) = x] ∧ [inf_K Φ > −∞ ∧ ∀θ : Φ(t(θ)) ≤ Φ(s(θ)) − δ] ⟹ ⊥.
Part D (cycle support under non-increase). If it is required only that every defined transition satisfy ΔΦ ≤ 0, then on any cycle every edge has ΔΦ = 0.
Proof.
Part A. Suppose the orbit x₀, x₁ = U(x₀), … does not terminate; then it is infinite. Since |K| < ∞, the |K| + 1 terms x₀, …, x_{|K|} lie in |K| states, so x_i = x_j for some 0 ≤ i < j ≤ |K|. Determinism gives x_{i+m} = x_{j+m} for all m ≥ 0, so the orbit is periodic from its i-th term with period p = j − i. If U is forward-total, termination is impossible and this branch is forced.
Part B. Applying the hypothesis step by step along a forward path x₀ → ⋯ → x_N gives Φ(x_N) ≤ Φ(x₀) − Nδ. Since Φ(x_N) ≥ inf_K Φ, we obtain Nδ ≤ Φ(x₀) − inf_K Φ, and taking the floor gives the bound. If there were a cycle, repeating it indefinitely would yield an infinite forward path, contradicting that bound; so no cycle exists.
Part C. Seriality allows indefinite extension from any x₀; Part B bounds path length. The two conflict.
Part D. Let the cycle be X₀ → X₁ → ⋯ → X_p = X₀. Telescoping,
Σ_{k=0}^{p−1} ΔΦ_k = Φ(X_p) − Φ(X₀) = 0,
and a finite sum of non-positive reals vanishes only if every term vanishes. ∎
4.3 The layering of the parts
Remark 4.4 (identity transitions are excluded automatically). Since the hypothesis of Part B is stated over transitions, a transition with identity projection is ruled out at once: s(θ) = t(θ) would give 0 ≤ −δ. So Corollary 4.8 needs no separate clause forbidding identity edges; it is a direct consequence of the hypothesis. This is a dividend of the labelled formulation of §3. Had the hypothesis been attached to configuration pairs instead, "no transition" and "a transition leaving the configuration unchanged" would not be distinguished, and the clause would have to be added by hand.
Remark 4.5 (Part B needs neither finiteness nor determinism). The proof of Part B uses three things only: Φ is bounded below, all transitions descend uniformly, and paths can be extended. Neither finiteness of K nor determinism of U enters. So Part B holds over non-deterministic relational systems as well, reading "every defined update" as "every allowed transition"; and the incompatibility of Part C is correspondingly free of finiteness and determinism, with its third clause read as seriality.
Finiteness and determinism are needed for Part A alone, and Part A yields recurrence, whereas Part B yields termination. They answer different questions and cannot substitute for one another.
Remark 4.6 (the cost of dropping determinism). If U is non-deterministic, Part A's conclusion must be weakened. An infinite path in a finite directed graph must visit some state infinitely often, so it comes to rest within a strongly connected component containing a directed cycle; that component may be a single vertex with a self-loop. It need not, however, become periodic, since the choice of branch may be irregular. What determinism buys is the step from "some state is visited infinitely often" to "the orbit is eventually periodic."
Remark 4.7 (this is not Poincaré recurrence). The conclusion of Part A must not be called Poincaré recurrence. The latter is an almost-everywhere return in measure-preserving dynamics [30], requiring preservation of measure and finiteness of volume; Part A requires only finiteness of the state set and determinism of the map, and yields eventual periodicity of each orbit rather than almost-everywhere return. Premises and conclusions differ, and the two must not be interchanged.
Corollary 4.8 (no-go for a strictly inward interior). On a fixed finite lattice, if every transition carries at least one strictly inward atomic transport and none outward, then Lemma 4.2 gives ΔΦ(θ) ≤ −δ_min < 0, so the hypothesis of Part B holds; seriality therefore yields a contradiction, and the orbit from n₀ terminates within
⌊ (Φ(n₀) − Φ_min) / δ_min ⌋
steps.
4.4 Exhaustiveness of Part D
Lemma 4.9 (potential change of a multi-transport transition). For any transition θ,
ΔΦ(θ) = Φ(t(θ)) − Φ(s(θ)) = Σ_{i ∈ I(θ)} [ r(y_i) − r(x_i) ].
Proof. Sum Lemma 4.2 termwise. ∎
Model 4.10 (radially non-increasing transition model). First, the configuration carries occupancy numbers only, with no internal labels, phases or momenta. Second, every transition θ is either idle or carries finitely many atomic transports, each satisfying r(y_i) ≤ r(x_i). Third, there is no creation or annihilation of particles.
Proposition 4.11. Under Model 4.10,
ΔΦ(θ) = 0 ⟺ r(y_i) = r(x_i) for every i ∈ I(θ).
Proof. By Lemma 4.9, ΔΦ(θ) is a sum of terms each of which is non-positive; the sum vanishes exactly when each term does. ∎
Remark. The right-hand side is vacuously true when I(θ) = ∅, so the idle transition is covered without a separate branch. And under radial non-increase, a transition with non-empty transport set whose projection is the identity must have all its transports on a single shell; that is the ring shift of Lemma 3.9.
Corollary 4.12. Under Model 4.10, every transition on a cycle is either idle or has all its transports on a single shell. This is Proposition 4.11 combined with Part D and needs no separate proof.
By Lemma 3.9 the identity edges are not empty: the ring shift is an identity edge on which something does occur. So what Corollary 4.12 locates is the address of a cycle at the configuration level, not at the occurrence level. That distinction is the type discipline of §3.
4.5 The combined statement
Corollary 4.13. In a finite deterministic configuration dynamics,
> every maximal orbit either terminates or is eventually periodic,
and
> an infinite orbit that never repeats a configuration is unavailable.
Events, however, may still never repeat. By the unfolding of Definition 3.5, ℰ is a tree and π : ℰ → 𝒳 is generally non-injective, so distinct histories reaching the same configuration are the norm. Return of configuration does not entail return of occurrence.
Remark 4.14. Forward completeness already excludes the terminating branch, so one must not write "either terminates or recurs." A finite deterministic system that is forward-complete has every orbit eventually periodic, with no room left for termination; the significance of the dichotomy is that avoiding recurrence requires abandoning forward completeness, and abandoning it delivers termination.
Remark 4.15 (Kill 5). What Part A refutes is only a real-valued rank defined on configurations and strictly increasing along every update. What it does not refute is an evolution parameter, an order of occurrence, or a direction of time. Take the two-state clock K = {0, 1} with U(0) = 1 and U(1) = 0: it is finite, deterministic and forward-total, so by Part A it is periodic, and indeed no τ : K → ℝ can satisfy both τ(1) > τ(0) and τ(0) > τ(1). Yet its direction, its distinguishable states and its per-step advance are all present. Moreover, by Definition 3.5 its occurrence unfolding is an infinite chain rather than a loop, so although the configuration has period two, the events never repeat.
> Periodicity of configuration does not entail the absence of time at the level of occurrence.
4.6 Relation to the numerical demonstration
The 25-cell toy of Appendix B gives an instance of Corollary 4.8 in which the step bound and the longest directed orbit found by enumeration coincide. That coincidence is a result of enumeration and does not follow from the bound; it therefore serves as one instance of tightness and not as evidence for the theorem. The theorem is given by Lemma 4.2 and Theorem 4.3 and does not rest on numerics.
5 The black-hole bridge and the exit matrix
5.1 Three bridges
Part B of the main theorem requires a bounded-below potential descending uniformly along every transition. Passing to this from the inwardness of the continuum theory requires a bridge, and there are three, ordered by strength.
Definition 5.1 (non-identity projection). H_occ : ∀θ ∈ Θ, s(θ) ≠ t(θ).
Definition 5.2 (radial potential descent). With Φ_r(n) = Σ_x n_x r(x),
H_r : ∃δ > 0, ∀θ ∈ Θ, Φ_r(t(θ)) ≤ Φ_r(s(θ)) − δ.
Definition 5.3 (Lyapunov potential).
H_Lyap : ∃Ψ : 𝒳 → ℝ bounded below, ∃δ > 0, ∀θ ∈ Θ, Ψ(t(θ)) ≤ Ψ(s(θ)) − δ.
Proposition 5.4 (ordering of the bridges).
H_r ⟹ H_Lyap ⟹ H_occ,
and neither converse holds.
Proof. For the first arrow take Ψ = Φ_r. For the second: if s(θ) = t(θ) then 0 ≤ −δ, a contradiction, so H_Lyap forces every transition to project non-identically.
The second converse fails because H_occ says only that configurations change and does not forbid their return; the configuration graph may contain a cycle while admitting no bounded-below uniformly descending potential at all.
The first converse fails because, if the same-shell directed subgraph is acyclic, the discrete gradient extension of Appendix A gives H_Lyap with Ψ = Σ_x n_x[r(x) + εf(x)]; but that Ψ is not Φ_r, and a same-shell edge gives ΔΦ_r = 0, so H_r fails. ∎
> The main theorem requires H_Lyap, not necessarily H_r.
Remark 5.5 (what the title refers to). The radial potential is the most basic candidate and the discrete gradient extension is its general completion; "radial-potential lifting" in the title names that candidate and does not assert that the main theorem admits only that one route.
5.2 The gap
The left end, inherited. In the trapped region every future-directed causal direction strictly decreases r (Proposition 2.4). What this constrains is worldlines and events.
The right end, required. H_Lyap. What this constrains is transitions and a potential over them.
The gap. There is no automatic passage between the two, and the obstruction has two independent halves.
First, the projection may be unfaithful. By Lemma 3.9 there is a θ with M(θ) ≠ ∅ and s(θ) = t(θ). So a non-trivial transition does not entail a change of configuration, and H_occ generally fails — and H_occ is itself weaker than H_Lyap. This half requires the synchronous convention.
Second, change of configuration does not entail descent of the potential. A single same-shell transport M(θ) = {x ⇝ y} with r(y) = r(x) gives s(θ) ≠ t(θ), so H_occ holds on that transition, while ΔΦ_r(θ) = 0, so H_r fails. This half does not require the synchronous convention and holds equally under sequential single hops. Excluding it would require proving the same-shell directed subgraph acyclic, which is H_tang of Appendix A, and that bridge is currently open.
> Strict inwardness of worldlines and events does not entail a bounded-below uniformly strictly descending potential over configurations.
The two halves are independent and must be delivered separately. Delivering the first gives H_occ and is still not enough; delivering the second allows a potential to be assembled. Deliver one and omit the other, and the main theorem still does not apply.
5.3 Three representative realisations
Three minimal representative realisations are considered below. This does not exhaust the space of timings; random parallel updating, block synchrony and finite-depth local circuits are further realisations not treated here.
First, sequential single hop. The ring shift does not belong to Θ, but the interior cells of a saturated region have no legal hop and are static, whereas the continuum theory requires the worldlines there to advance at every step. So this realisation does not carry inwardness inside a saturated region. The duration of that stasis is bounded below; see §6.3.
Second, synchronous exchange without a radial constraint. The ring shift belongs to Θ, and by Lemma 3.9 H_occ fails.
Third, synchronous exchange in which every allowed transition satisfies M(θ) ≠ ∅ and r(y_i) < r(x_i) for every i ∈ I(θ). The condition M(θ) ≠ ∅ must be written explicitly to exclude the idle transition: an empty transport set makes strict inwardness vacuously true while ΔΦ_r = 0, so H_r would fail. With idle excluded, ΔΦ_r(θ) ≤ −δ_min holds by definition, H_r is established, H_Lyap follows by Proposition 5.4, and Parts B and C of the main theorem fire.
Two supports for the third realisation.
Under strict inwardness the ring shift does not exist. Suppose M(θ) contains a closed chain x₁ ⇝ x₂, …, x_k ⇝ x₁ with every transport strictly inward. Then r(x₂) < r(x₁), and so on to r(x₁) < r(x_k), and chaining gives r(x₁) < r(x₁), a contradiction. So the first clause automatically kills the counterexample to the second. This is stronger than the radially non-increasing version of Corollary 6.11, which yields only that a ring shift must lie on a single shell; here it does not exist at all.
A saturated interior can still move, by an open chain rather than a closed one. Take M(θ) = {x₁ ⇝ x₂, …, x_{k−1} ⇝ x_k} with x₁ outer and x_k inner. Then n_{x₁} decreases by one, the middle cells are unchanged, and n_{x_k} increases by one; legality requires only n_{x₁} > 0 and n_{x_k} < n_max, so the entire middle may be saturated without obstruction.
And so the main theorem fires. Each transition gives ΔΦ_r(θ) = r(x_k) − r(x₁) ≤ −δ_min, and Φ_r is bounded below, so Part B bounds the orbit length and Part C makes forward totality impossible. As to where the room at the innermost end comes from: either it was never saturated, in which case the potential descends until saturation is complete, or it is a sink, which is the internal-termination row of the exit matrix. Both routes are conclusions of Part C.
| Realisation | Consequence |
|---|---|
| sequential single hop | interior cells static; inwardness not carried |
| synchronous exchange, no radial constraint | ring shift in Θ; H_occ fails |
| synchronous, idle excluded, every hop strictly inward | H_r holds; the main theorem fires and forward totality is lost |
> If the bridge is broken, the model's pure occupancy configuration dynamics cannot by itself claim to carry inwardness. If the bridge holds, forward totality is lost on the spot. Both sides pay.
Remark 5.6 (a narrowing that must be written). What a broken bridge refutes is only the claim that a pure occupancy configuration dynamics carries inwardness by itself. The model may still carry inwardness in a labelled complete state, in current variables, in event relations, in a causal set, or in momentum space; what is refuted is only the claim that this content has already been projected onto a uniform descent of Φ_r. This narrowing is consistent with the paper's own three-domain discipline and is not a retreat.
5.4 Where the axis lies
It might be thought that enriching the configuration space rescues H_occ. It does: adding a finite set of labels, such as a bounded local flow direction or finitely many particle tags, keeps |𝒳| finite while the ring shift cyclically permutes labels, so s(θ) ≠ t(θ) and H_occ holds. Finiteness and H_occ can therefore be had together; they are not alternatives.
But this does not rescue the bridge. Φ_r is blind to labels, so however the ring shift permutes them, ΔΦ_r remains zero. Recovering H_occ contributes nothing to H_Lyap.
> H_occ is not the right axis; H_Lyap is.
The tension should therefore be stated differently. Not as "labels cost finiteness," but as: the closer a state space comes to physical completeness, the harder its finiteness is to establish. Finite labels buy both finiteness and non-identity projection, and cannot by themselves establish a strictly descending potential; it is continuous phase, momentum, or unbounded history variables that return finiteness to the status of an open question.
5.5 The exit matrix
The main theorem has two conclusion lines, potential obstruction and orbit recurrence. They answer different questions, and a single physical exit damages different things on each line, so a cross matrix is given in place of two sets of prose.
| Physical exit | What it breaks on the potential line | What it breaks on the recurrence line |
|---|---|---|
| outward escape or output | outward transports may occur, or the orbit leaves the domain | breaks closure |
| internal termination | breaks forward totality | is the terminating branch |
| infinite or growing state space | Ψ unbounded below, or the uniform gap vanishes, or Ψ no longer captures all change | breaks finiteness |
| identity-projecting transition | ΔΨ = 0, breaking uniform descent | does not prevent recurrence; typically yields fixed points |
| same-shell transport | breaks H_r; whether it breaks H_Lyap is decided by acyclicity of the same-shell subgraph | can support a cycle |
| outward radial transport | breaks radial non-increase | need not leave the system, so is not the same as escape |
| non-autonomous evaporation | Ψ and Θ vary with the remaining mass | breaks the autonomous fixed state space |
| hidden internal degrees of freedom | Ψ fails to capture their change | the premise of a complete finite state fails |
Remark 5.7. The same-shell row and the identity-projection row must be told apart: the former has s(θ) ≠ t(θ) with ΔΦ_r = 0, the latter has s(θ) = t(θ). Both break H_r, by different routes; these are the two halves of the gap in §5.2.
Remark 5.8. The identity-projection and same-shell rows are given explicit constructions by Lemma 3.9 and by a single same-shell transport. The internal-termination and infinite-state-space rows also have minimal counter-models: 0 → 1 with Succ(1) = ∅, and 0 → 1 → 2 → ⋯. Neither has any route of escape, and they fail forward totality and finiteness respectively, so trappedness alone entails neither. The remaining rows are registrations of possibility, not realised constructions.
6 Two applications
The two items of this section rest on different things. The first is an application of the main theorem, taking energy as the potential; the second consists of a direct argument within a model and an induction on rounds.
6.1 Exact recurrence against positive net outflow
Theorem 6.1. Let 𝒯 = (𝒦, Θ, s, t, M) be an autonomous transition system on a fixed complete state space, let E : 𝒦 → ℝ be its energy, and let every transition emit q(θ) ≥ 0 outward, so that
E(t(θ)) = E(s(θ)) − q(θ).
Then on any exact cycle, that is on a transition string θ₁⋯θ_p composable end to end with s(θ₁) = t(θ_p), every segment has q(θ_k) = 0.
Proof. Take Ψ := E. Since q ≥ 0, every transition satisfies ΔE(θ) = −q(θ) ≤ 0, which is the hypothesis of Part D. By Part D every edge on the cycle has ΔE = 0, so q(θ_k) = 0. ∎
Remark 6.2. This is not a new argument but an application of Part D with energy in place of the occupancy potential. What it exhibits is that the main theorem is not confined to occupancy: any quantity monotone along transitions may be substituted.
Remark 6.3 (output must attach to transitions, not configurations). q must be written q(θ). The same source-target pair may be realised by different transitions whose outward emission differs; writing q(x) loses that distinction and leaves the telescoping sum with nothing to attach to. This is a direct consequence of the labelled formulation of §3.
Remark 6.4. This does not deny instantaneous radiation. What it denies is the coexistence of persistent net emission with an exact cycle.
A common evasion and why it fails. It might be said that the outward output carries energy but not configuration, so the configuration may still return exactly. This cannot be saved, because energy belongs to the complete state: delete it from the definition of the state and the update is no longer autonomous; include it and it descends monotonically, so the state cannot return during evaporation; let the state space shrink with the mass and there is no longer a single autonomous system on a fixed set. The three routes abandon autonomy, return and finiteness respectively; all three appear in the exit matrix of §5.5.
Remark 6.5. The analysis of these three routes is a remark on this theorem and is not counted as a separate refutation. It is not a new partition of the space of possibilities but an attempt to evade Theorem 6.1.
The incompatibility.
> H_auto ∧ H_rec ∧ H_flux ⟹ ⊥
Here H_auto says the system is throughout described by autonomous transitions on one fixed complete state space; H_rec says that x_{k+p} = x_k on some eventual cycle; and H_flux says that on that same cycle at least one segment has q(θ_j) > 0, equivalently that the cycle sum Σ_{j=k}^{k+p−1} q(θ_j) > 0.
The three conditions must be attached to the same orbit or the same cycle class, and this must not be passed over. Otherwise it is logically possible for the system to possess a radiationless exact cycle in one place and a transient orbit with positive outflow elsewhere, and the two would not conflict.
Remark 6.6 (why the renaming). The condition was formerly written as full closure. If that already means "the complete state has no output at all," it is definitionally at odds with positive outflow, the recurrence clause becomes redundant, and the theorem degenerates into a tautology. Written as H_auto, the theorem says: on a fixed autonomous complete state space, exact state recurrence and persistent net energy loss cannot coexist. Each of the three conditions then carries content and none is redundant.
This must be marked as a revision of an existing statement. Info-4 [9], §4.4, seventh point, holds that gravitational waves cross the horizon outward through the Planck substrate, and that paper's §10, item twelve, lists this as a falsifiable prediction. Its conflict with the present paper must be stated precisely: if the complete state space is at once fixed, autonomous, finite and forward-total, so that by Part A it enters an exact recurrence branch, then persistent positive net outflow is incompatible with it. Theorem 6.1 by itself does not exclude a forward evaporation history in a non-recurrent, non-autonomous or infinite state space. The two commitments must be reconciled, or the channel must be distinguished; this paper does not make that choice.
The channel question. If outward broadcast is retained, trappedness must be restricted to some projection channel π_conf, and it must separately be shown that the critical surface for non-escape in that channel is still exactly r_s. Moreover, against a dynamical evaporating background, the event horizon and the apparent horizon are in general distinct surfaces [22,23] — the former a teleological null surface depending on the global future, the latter a quasi-local marginally trapped surface — so a single static r_s cannot represent every definition of trappedness at once. This paper raises the question and does not resolve it.
6.2 Local exclusion
The sequential case.
Lemma 6.7 (local exclusion under sequential single hops). Under the sequential single-hop convention, where |M(θ)| ≤ 1 and a transport is legal exactly when the source is occupied and the target has room — the legality criterion of an exclusion process [24,25] — suppose
n_x = n_max and n_y = n_max for every y ∼ x.
Then in this step there is no legal transition with x as source or target, so n_x is unchanged.
Proof. A transition with x as source needs some neighbour with room, and all neighbours are full. A transition with x as target needs n_x < n_max, and x is itself full. ∎
Remark 6.8 (the clause on x itself cannot be dropped). If only the neighbours are assumed saturated and x is not, then when n_x < n_max a neighbour can send a unit into x and n_x changes. A statement omitting that clause is false.
The synchronous case.
Under synchronous exchange there is no comparable local invariance: by the open chain of §5.3, even when every immediate neighbour of x is full, x may still serve as the start of an open chain leading to distant room and thereby change.
Proposition 6.9 (invariance condition under synchronous exchange). Under synchronous exchange, suppose n_x = n_max. Then every legal transition from the current configuration leaves n_x unchanged if and only if there is no allowed path from x to any vacancy.
Proof. Legality requires 0 ≤ t(θ)(z) ≤ n_max everywhere, so any cell z with a net gain satisfies s(θ)(z) < n_max and was therefore initially vacant.
If an allowed path runs from x to some vacancy, an open-chain transport along it gives a legal transition decreasing n_x, so not every transition leaves n_x unchanged.
Conversely, suppose no such path exists. Since n_x = n_max, x cannot gain. If x were to lose, then regarding M(θ) as an integer flow on the graph and applying the decomposition of a finite flow, there is a path from x to some net-gaining cell; that cell was initially vacant, giving an allowed path from x to a vacancy, contrary to assumption. So x neither gains nor loses and n_x is unchanged. ∎
Remark 6.10. This is a global condition, not a local one. The name "local exclusion" therefore fits the sequential convention only; under synchronous exchange what remains is a statement about connectivity.
What the lemma does not deliver.
First, it is not permanent. A neighbour may first discharge into an unfilled cell further out, creating room, after which the transport becomes available. What is shown holds for the current step only.
Second, it is not the absence of a transition. The synchronous closed chain is the ring shift of Lemma 3.9, with M(θ) ≠ ∅ and s(θ) = t(θ). Wherever "occupancy unchanged" is written it must not be read as "nothing happened."
Third, it fixes occupancy only, not the complete state. Momentum exchange, phase evolution, permutation of internal labels, stress transmission, collective modes and lattice reconnection may all occur with occupancy unchanged.
The address of the ring shift.
Corollary 6.11. Under a radially non-increasing model, any ring shift lies within a single shell.
Proof. A ring shift leaves the configuration unchanged, so the sum of ΔΦ_r over its constituent transports is zero; each term is non-positive, so each vanishes, so each transport is same-shell; and a chain all of whose transports are same-shell lies on one shell. ∎
Remark 6.12. This is Proposition 4.11 applied to the ring shift. Drop radial non-increase and the ring shift may mix radially; add strict inwardness and, by §5.3, it does not exist at all. The address of the ring shift is therefore decided by the radial condition, not by geometry.
6.3 The influence cone and its volume
Initial vacancies and a propagation bound.
Definition 6.13. Let the set of initially vacant cells be
S₀ = { x ∈ V_cell : n₀(x) < n_max }.
Proposition 6.14. Suppose the update satisfies local dependence: the state of a cell at round t + 1 depends only on its graph-distance-one neighbourhood at round t, and a fully saturated neighbourhood remains saturated in the absence of outside influence from a vacancy. Then for an initially saturated cell x,
t_thaw(x) ≥ d_G(x, S₀).
Proof. By induction on rounds. The claim is that after t rounds only cells with d_G(x, S₀) ≤ t can have changed. At t = 0 nothing has changed. Suppose the claim holds through round t, and take a cell x with d_G(x, S₀) > t + 1. Every neighbour y satisfies d_G(y, S₀) ≥ d_G(x, S₀) − 1 > t, so by the inductive hypothesis the whole distance-one neighbourhood of x is unchanged at round t and remains fully saturated; by the second clause of local dependence, x is unchanged at round t + 1. Hence every cell changed after round t + 1 satisfies d_G(x, S₀) ≤ t + 1. ∎
Remark. This proof does not use the step "the target must have had room beforehand," and so holds under synchronous exchange as well; sequential single hopping is a special case of local dependence.
Remark 6.15 (S₀ in place of an inner boundary). Measuring from the inner boundary of a saturated region introduces an off-by-one: a boundary cell is at distance zero from that boundary while its first change still generally requires a step. Measuring from S₀ removes the offset.
The influence cone.
Definition 6.16. Let
𝒞_t = { x ∈ V_cell : d_G(x, S₀) ≤ t }.
By Proposition 6.14,
> the set actually affected after t rounds is contained in 𝒞_t.
Remark 6.17 (what is computed is the envelope, not the actual set). The geometric calculation below gives |𝒞_t ∩ B| / |B|, the fraction of the saturated region occupied by the influence cone, and this is an upper bound on the actually affected volume rather than its value. If a single global time step permits only one atomic hop anywhere in the lattice, then after t steps at most O(t) cells have changed, far fewer than a layer of thickness t; the formula below corresponds instead to rounds of parallel local updating in which causal influence propagates at most one edge per round. Without this distinction a reader will mistake the envelope volume for the volume actually changed in some particular history.
The scaling.
On the cubic six-neighbour lattice the graph distance is the L¹ distance. The L¹ ball of radius t is an octahedron whose extent along a unit normal n̂ is t h(n̂) with h(n̂) = max_i |n_i|. So when S₀ lies outside a saturated region of radius R,
where
⟨h⟩ = (6/π√2) arctan(1/√2) = 0.8311896, 3⟨h⟩ = 2.4935689.
Remark 6.18 (two levels of correction). The leading coefficient is the t/R → 0 limit. Finite thickness contributes an O(t²/R²) correction with an empirical coefficient of about −1.65; lattice discreteness contributes an O(1/R) correction. The two must not be run together in one sentence.
Remark 6.19 (lattice dependence). The value 2.4936 is a joint product of the interior-cell criterion and six-neighbour adjacency. A continuum shell one cell thick gives 3/R; eighteen-neighbour and twenty-six-neighbour adjacency and Voronoi cells all give different coefficients. Only R⁻¹ is universal. The static skin fraction is this same formula read at t = 1, so the static geometric ledger and the dynamical envelope are one scaling read at two thicknesses.
Conclusion.
> Saturation does not entail permanent stasis; and if thawing propagates from initial vacancies by local finite-speed updating, then the actually affected set is enveloped by 𝒞_t and cannot arrive earlier than the graph distance allows.
This is a statement of an upper bound, not an assertion about what happens. A model may perform no update at all, or its actual influence may be far slower than the envelope.
The initial bifurcation among the possible outcomes lies where the vacancies are; once vacancy, stress or a change of topology is generated, its influence may propagate inward at a rate constrained by Proposition 6.14. That the initial bifurcation lies at the surface may be asserted; that it remains forever confined to one layer may not.
Remark 6.20 (feedback to §5.3). Under sequential single hops the interior cells of a saturated region have no legal transition by Lemma 6.7, and by Proposition 6.14 that stasis persists for at least d_G(x, S₀) rounds; yet the continuum theory requires the worldlines there to advance at every step. So that realisation does not carry inwardness, which is the quantitative support for the first row of §5.3.
7 Discussion and conclusion
7.1 Bridges not yet built
Three things are exposed here and not delivered.
H_Lyap. The inwardness given by Proposition 2.4 must be lifted to a bounded-below potential descending uniformly along every transition before Part B of Theorem 4.3 applies. By §5.2 that lifting faces two obstructions: the projection may be unfaithful (Lemma 3.9), and change of configuration does not entail descent of the potential (same-shell transport). This is the paper's central opening.
H_tang. The continuum argument of Appendix A, in its present form, does not constitute a proof of H_tang: what it establishes is a statement about the continuum limit, while H_tang is a statement about a finite graph, and no bridge between them has been given. This must be read precisely: it is a statement about that argument, not about the implication. To show that continuum vanishing vorticity does not entail discrete same-shell acyclicity would require an actual counter-model, a sequence of increasingly fine lattices each containing same-shell directed cycles whose coarse-grained tangential flow converges weakly to the zero field. Planck-scale micro-circulation may in principle cancel under coarse-graining, but no refining sequence meeting all the requirements has been supplied here, so the item is listed as open rather than refuted.
Completeness and autonomy of K. If phase, momentum, labels, graph topology or history affect the future, then the genuine complete state space is not the occupancy configuration space, and Part A of Theorem 4.3 loses its object.
Only what this paper actually touches is listed. The full set of posits belonging to a future core paper is not, for the reason given in §1.6.
7.2 Forward completeness splits in two
What has been called forward completeness here contains two clauses, only one of which enters any proof, so they must be written separately.
Combinatorial forward completeness. ∀x₀, ∀h ∈ Hist_max(x₀), |h| = ∞. This clause enters Theorem 4.3.
Physical regularity. sup_n |O_a(x_n)| < ∞ along every history, and the conservation ledger is defined at every step. This clause enters no proof.
So the accurate claim of this paper is that it gives necessary conditions for combinatorial forward completeness and does not establish physical regularity. Without this separation, boundedness would appear load-bearing while in fact going unused.
7.3 The refutations of this paper
7.3.1 What counts as a refutation
A negative result counts as a refutation exactly when it narrows the space of possibilities, so that anyone subsequently constructing a discrete interior must go around it. A record of a view once held and later abandoned does not count. The test is not how hard the negative was to obtain, but whether the negatives partition the space or merely repeat.
On that test this paper has nine. The number is not a measure of value; a paper does not gain weight from the multiplicity of its refutations.
7.3.2 The table
Group A: over-inheritance. Taking too much from the continuum theory.
| # | Hypothesis | How refuted | Source |
|---|---|---|---|
| Kill 1 | degeneration of the lapse at the horizon entails no global time direction in the interior | type error; a nowhere-vanishing timelike field on ingoing EF coordinates with g(X,X) ≤ −15/8 | §2.2, §2.3 |
| Kill 2 | the Kretschmann scalar, or any fixed dimensionful curvature magnitude I = I⋆ > 0, serves as a mass-independent threshold locating r_s universally | K(r_s) = 3c⁸/4G⁴M⁴ becomes arbitrarily small with mass, so no fixed threshold meets r_s for all M | §2.4 |
| Kill 3 | every transition projects to a non-identity change of configuration (H_occ) | the ring shift: M(θ) ≠ ∅ with s(θ) = t(θ) | Lemma 3.9 |
Group B: over-inference. Taking too much from the discrete structure.
| # | Hypothesis | How refuted | Source |
|---|---|---|---|
| Kill 4 | simple connectedness forbids directed cycles in the update relation | an orientation bundle is a topological object and a directed cycle a combinatorial one; explicit construction supplied | Appendix B |
| Kill 5 | periodicity of configuration entails the absence of time at the level of occurrence | the two-state clock 0 → 1 → 0; the unfolding is a tree | Remark 4.15 |
| Kill 6 | local saturation entails permanent bulk blockage or a stable core | under sequential hops a neighbour may discharge first; under synchronous exchange an open chain traverses a saturated middle directly. The refutation holds under both conventions; only the rate belongs to the former | Lemma 6.7, Proposition 6.14, §5.3 |
| Kill 7 | trappedness alone entails recurrence or forward completeness | two counter-models, neither escaping and neither recurring: 0 → 1 with Succ(1) = ∅, terminating; and 0 → 1 → 2 → ⋯, with infinite state space. So H_trap entails neither H_total nor H_finite | §5.5, Remark 5.8 |
Group C: mutual incompatibility.
| # | Hypothesis | How refuted | Source |
|---|---|---|---|
| Kill 8 | a strictly spherically symmetric tangential circulation exists | Stokes, together with H¹_dR(S²) = 0 and the isotropy subgroup | Appendix A |
| Kill 9 | exact recurrence can coexist with persistent positive net outflow | taking energy as the potential, the terms on a cycle are non-negative and sum to zero, so q(θ) = 0 on every segment | Theorem 6.1 |
Remark (on the scope of Kill 2). What is refuted is only the fixed dimensionful magnitude threshold as stated, not every local invariant, and not a universal claim about all curvature magnitudes; the latter would require a separate dimensional classification theorem, whereas this paper computes only K. The Karlhede invariant 𝔎 = R^{λμνκ;η}R_{λμνκ;η} is, for Schwarzschild, 720 m² r³ (r − 2m) / r¹², which vanishes and changes sign exactly at r = 2m for every mass [34]. So a local invariant can indeed mark the horizon, but it does so by a change of sign rather than by attaining a magnitude. This has the same shape as the theme of the paper: rate and magnitude fail, structural transition succeeds.
Remark (on the evasion "energy but not configuration"). This is not counted as a separate refutation. It is not a new partition of the space of possibilities but an attempt to evade Kill 9, and the failure of its three routes is recorded as a remark on Theorem 6.1 (Remark 6.5).
7.3.3 The shape of the squeeze
Groups A and B form a squeeze whose shape is that established in [33], §10. Over-inheritance would carry the criteria and symmetries of the continuum theory directly into the discrete layer; over-inference would read permanence, globality or recurrence directly off the discrete structure. Both are refuted, and what remains is a narrow corridor: a statement about a discrete interior must declare its bridges one by one. Section 2.4 shows the shape most plainly, where the local strength threshold and the lapse are both refuted while marginal trappedness survives.
7.3.4 What does not count as a refutation
Conjectures never published, and their corrections, enter neither the text nor the appendices. This framework does retain negative results — Paper 1 [31], §5.1, keeps in its main text the partial failure of its own computation, namely the non-monotone rise-width of the K3 front sharpening, judged FAIL in its Table 2 — but that failure was an output of its algorithm and therefore a result. A publishable negative must be a proposition or an enumeration, not a record of process.
7.4 What has been moved out of this paper
The rate law for universal evaporation and its empirical pressure tests bear no logical dependence on the theorems here, and belong to the rate paper of the framework's information-theory series or to a separate short note on negative results. The discipline of preregistration travels with them: the next version of a rate law must fix its ordinary-matter limit before the data are computed, and must not add a suppression function after seeing the constraint, on pain of degenerating into unfalsifiability.
The crossing of core radius and horizon radius at sub-Planckian scale, whose algebra is sound but whose physical extrapolation exceeds the domain of credibility, is likewise moved out.
7.5 The minimal entry point for what follows
If the work is continued, the sole entry point is H_Lyap, in the form of a question:
> On what configuration space does there exist a bounded-below potential descending uniformly along every transition?
This is strictly stronger than asking where H_occ holds. By §5.4, a finite set of labels suffices to make H_occ hold without losing finiteness, yet the occupancy potential is blind to labels and so nothing is contributed to uniform descent. What the next paper must deliver is a potential, not fidelity of projection.
The genuine tension should be stated in the same way: not that labels cost finiteness, but that the closer a state space comes to physical completeness, the harder its finiteness is to establish. Finite labels buy both finiteness and non-identity projection and cannot by themselves establish a strictly descending potential; it is continuous phase, momentum, or unbounded history variables that return finiteness to the status of an open question.
7.6 Conclusion
What this paper delivers is a framework for auditing the assumptions of discrete-interior models, not a verdict on what the interior of a black hole is. Its mathematics is elementary: a quantity bounded below cannot descend uniformly without end, and a finite deterministic system must return. None of what is specific to black holes lies in that piece of combinatorics. It lies in a single question:
> Can the inwardness of events and worldlines in the standard theory be lifted to a uniformly strictly descending potential on the complete discrete configuration space?
And by §5.3, both answers carry a cost. So this paper is not a report of a gap. What it establishes is that anyone proposing to carry the inwardness of the trapped region by way of a finite, forward-complete discrete occupancy dynamics has either not truly carried it or has already lost forward completeness. Both sides pay, and what is paid on one side cannot be set against the other.
What this no-go constrains is the licence to make a claim, not the construction of nature. Nothing here asserts what the interior of a black hole is, and nothing here places any particular model on one side or the other; what is established is the ledger for both sides, and deciding where a model belongs requires checking, one at a time, its timing convention, the existence of its potential, and the finiteness of its state space.
This restraint is not modesty. It is forced by the paper's own type discipline. The rule laid down in §3 is that a conclusion in one domain may not stand in for an assertion about another without an explicit bridge. What this paper charges throughout is that someone has passed from a statement about worldlines to a statement about configurations without building a bridge; if the paper itself passed from a conclusion about a class of models to an assertion about the interior of a black hole, that would be the same error one level up. The restraint and the argument have a single source, and abandoning the former wounds the latter.
The shape of the nine refutations bears this out. Seven of them block inferences, in the form that some premise does not license some conclusion; only two are theorems at the level of the objects, namely that no strictly spherically symmetric tangential circulation exists, and that exact recurrence and persistent positive net outflow are incompatible. The bulk lies in the blocking of inferences and the minority in results about objects, and that is the proportion appropriate to a paper treating an ontological question by formal means.
8 Status map
| Item | Level |
|---|---|
| Main theorem | |
| Theorem 4.3 Part A, orbit dichotomy | proved; requires finiteness and determinism |
| Theorem 4.3 Part B, uniform descent obstruction | proved; requires neither; hypothesis stated over transitions |
| Theorem 4.3 Part C, forward totality against uniform strict descent | proved |
| Theorem 4.3 Part D, vanishing potential change on a cycle | proved |
| Lemma 4.9, potential change of a multi-transport transition | proved |
| Proposition 4.11, characterisation of ΔΦ(θ) = 0 | proved, conditional on Model 4.10 |
| Corollary 4.8, no-go for a strictly inward interior | proved, conditional on a fixed finite lattice |
| Domains and transitions | |
| three-domain separation and the type-checking rule | formal discipline |
| labelled transition system, Definition 3.3 | formal object; the configuration graph is its quotient, the unfolding its strings |
| occurrence unfolding as semantic convention, Definition 3.5 | convention, with a cost; not an ontological claim |
| Lemma 3.9, ring shift | proved, conditional on synchronous exchange |
| Corollary 3.10, H_occ generally fails | proved |
| Inherited | |
| strictly inward causal direction in the trapped region, Proposition 2.4 | standard result |
| Misner–Sharp criticality and marginal trapping coincide under spherical symmetry | standard result |
| The three bridges | |
| H_occ, non-identity projection | generally false (Kill 3) |
| H_r, radial potential uniform descent | not established |
| H_Lyap, bounded-below uniformly descending potential | not established; the paper's central opening |
| H_tang, same-shell subgraph acyclic | open: neither proved nor refuted; the continuum argument supplies no discrete bridge and no counter-model has been given |
| Proposition 5.4, ordering of the bridges | proved |
| Refutations | |
| Kill 1 through Kill 9 | proved; sources in §7.3.2 |
| Applications | |
| Theorem 6.1, exact recurrence against positive net outflow | proved, conditional on H_auto |
| Lemma 6.7, local exclusion under sequential hops | proved; requires x itself saturated |
| Proposition 6.9, invariance condition under synchronous exchange | proved by flow decomposition; the condition is global, not local, and is quantified over all legal transitions |
| Proposition 6.14, propagation bound | proved, conditional on local dependence |
| influence-cone envelope fraction 3⟨h⟩t/R | leading coefficient computed; what is computed is an envelope upper bound, not the actually affected value; the coefficient is lattice-dependent and only R⁻¹ is universal |
| Not treated here | |
| existence of a material core; an interior layer state; numerical occupancy or density bounds | not claimed |
| resolution of the singularity; the information paradox; the Page curve; Kerr | not treated |
| observational projections | not given |
| the rate law for universal evaporation and its empirical tests | moved out, to the information-theory series |
Appendix A The continuum spherical-symmetry no-go, and the same-shell bridge
The theorem and its proof
Theorem A.1 (Kill 8). Let v be a smooth tangential field on the sphere S², let α = v♭ be its dual one-form, and let dα = ω dA define its vorticity. If ω is an SO(3)-invariant scalar, then ω ≡ 0, v is a gradient field, and there is no non-trivial closed orbit.
Proof. In three steps.
First, the integral vanishes. S² has no boundary, so by Stokes' theorem [26]
∫_{S²} ω dA = ∫_{S²} dα = ∫_{∂S²} α = 0.
Second, constant and zero. Being an SO(3)-invariant scalar function on the sphere, ω is constant. A constant with vanishing integral is identically zero.
Third, gradient and no closed orbit. ω ≡ 0 means dα = 0, so α is closed. Since H¹_dR(S²) = 0, a closed form is exact: there is f : S² → ℝ with α = df, and raising the index gives v = ∇f. Along its flow df/dt = |∇f|² ≥ 0, strictly increasing away from critical points, so f is monotone along the flow and no non-trivial closed orbit exists. ∎
Remark (degeneracy of the strong hypothesis). If instead v itself is assumed strictly SO(3)-invariant, the conclusion is stronger and the proof shorter: at any p ∈ S² the isotropy subgroup is the SO(2) of rotations about the axis through p, acting on T_p S² ≅ ℝ² by rotation, and the only vector invariant under a non-trivial rotation is zero, so v(p) = 0 everywhere. Under the strong hypothesis the theorem is therefore trivial; the value of Theorem A.1 lies in its weaker hypothesis, requiring only that the vorticity be invariant.
Disambiguation: symmetry of the field against symmetry of the system
What Theorem A.1 establishes is strict spherical symmetry of the field, not of the system. Spherically symmetric dynamics fully admits non-symmetric solutions; spontaneous symmetry breaking is precisely the case of a symmetric law with a non-symmetric state, and a black-hole interior microstate has no reason to be SO(3)-invariant.
> What is established: no spherically symmetric circulation exists. What is not established: no circulation exists in a spherically symmetric system.
Without this sentence Theorem A.1 will be read as far stronger than it is. It should also be read together with the open bridge below, so that no contradiction arises:
> A non-zero smooth continuum tangential circulation must break strict spherical symmetry; yet discrete micro-circulation may disappear in the continuum limit, so its existence need not cost the macroscopic continuum field its spherical symmetry.
The first clause is the content of Theorem A.1; the second is why that theorem does not suffice to establish H_tang. The two stand together without conflict.
The hairy ball theorem provides no exit
The hairy ball theorem [27] guarantees that any continuous tangential field on S² has a zero, but zeros are entirely compatible with a gradient field and do not generate circulation of themselves: the critical points of a gradient field are its zeros, and their presence does not produce closed orbits.
A correction concerning punctures. Removing a single point does not produce non-trivial cohomology: S² \ {p} ≅ ℝ² and H¹_dR(ℝ²) = 0. At least two punctures are needed, giving S² \ {p, q} ≅ S¹ × ℝ with H¹_dR ≠ 0.
The correct statement is therefore: if at least two singular defects, a non-trivial puncture structure, or distributed vorticity are admitted, then the smooth global hypothesis of Theorem A.1 fails and what is under discussion is a different model.
The discrete limitation
A finite complex has only a finite symmetry group. The spherical subdivision used in the numerics of this paper has only icosahedral symmetry, of rotation order 60, which is not the continuous SO(3). Theorem A.1 therefore cannot be pressed directly onto a finite toy. This limitation is not technical caution; it is the root of the open bridge below.
The same-shell bridge, and why it is not established
Definition A.4. Partition the update edges into E₋ = {x → y : r(y) < r(x)} and E₀ = {x → y : r(y) = r(x)}. Write
H_tang : ∃f : V_cell → ℝ, ∃η > 0, ∀(x → y) ∈ E₀, f(y) − f(x) ≤ −η.
Proposition A.2. On a finite directed graph, H_tang holds if and only if the same-shell directed subgraph is acyclic.
Proof. If acyclic, a topological sort [28,29] gives a linear order; take f to be the negative of the position in that order, suitably scaled, to obtain strict descent with η > 0. Conversely, if there is a cycle x₁ → ⋯ → x_k → x₁, summing around it gives 0 = Σ[f(x_{i+1}) − f(x_i)] ≤ −kη < 0, a contradiction. ∎
Corollary A.3. H_tang is equivalent to the conclusion it is meant to establish. What follows from this, and what does not, must be distinguished. It follows that the bridge is not a condition weaker than its conclusion. It does not follow that some other independent hypothesis cannot entail it: a hypothesis may perfectly well entail a condition equivalent to a conclusion. So what may be asserted is only this: this paper has not supplied a bridge from F5_continuum to H_tang, not that the implication has been refuted.
Theorem A.1 gives vanishing vorticity in the continuum limit, and vanishing vorticity gives a gradient field, and a gradient field has no closed orbit in the continuum sense. But this does not yield acyclicity of the same-shell subgraph on a finite lattice: coarse-graining can erase Planck-scale discrete circulation, with micro-vortices of opposite sign cancelling so that the continuum limit has ω ≡ 0 and is strictly spherically symmetric, while the finite same-shell subgraph still contains directed cycles.
> Strict continuum spherical symmetry can motivate same-shell absence of circulation; it does not suffice to prove acyclicity of the discrete same-shell subgraph.
To establish that the implication fails would require a genuine counter-model: a sequence of increasingly fine lattices, each containing same-shell directed cycles, whose coarse-grained tangential flow converges weakly to the zero field. Micro-circulation may in principle cancel under coarse-graining, but no refining sequence meeting all the requirements is supplied here, so the item is listed as open rather than refuted.
> F5_continuum ⟹ H_tang : open — neither proved nor refuted
The discrete gradient extension, a conditional remark
Suppose H_tang holds, with f and η. Let δ_r = min_{E₋}[r(x) − r(y)] > 0 and M_f = max_{E₋}|f(y) − f(x)| < ∞. Take 0 < ε < δ_r/M_f, or any ε > 0 if M_f = 0, and set
ψ_ε(x) = r(x) + εf(x), Φ_ε(n) = Σ_x n_x ψ_ε(x).
Then a same-shell edge gives ΔΦ_ε = εΔf ≤ −εη < 0, and an inward edge gives ΔΦ_ε ≤ −δ_r + εM_f < 0. With δ_ε = min{εη, δ_r − εM_f} > 0, every non-identity edge descends uniformly and Part B of Theorem 4.3 applies.
Remark (signs). If v = ∇f then f increases along the flow, so it must be paired with Φ′ = r − εf; alternatively take v = −∇f with Φ′ = r + εf. One or the other, not a mixture.
Status. This subsection is a conditional extension, not a result. Its condition H_tang is, by Proposition A.2, equivalent to the desired conclusion, so what is delivered is only that a combined potential can be assembled if the same-shell subgraph is acyclic, and not that it is.
Kerr
The hypothesis of Theorem A.1 is strict spherical symmetry. The axisymmetric case is not excluded by that theorem, since under axisymmetry ω need not be constant and positive and negative vorticity may cancel over the sphere to give a vanishing integral.
This paper does not claim that the required circulation exists in the interior of Kerr. All that may be written is that the case is not excluded by Theorem A.1.
Appendix B Numerics and the lattice
The 25-cell toy
The complex. The cells are {(r, t) : r ∈ {1,2,3,4}, t ∈ {0,…,5}} together with a centre cell, 25 in all. The radial coordinate of (r, t) is r, and that of the centre is 0.
Adjacency. Same-shell (r, t) ∼ (r, t ± 1 mod 6); radial (r, t) ∼ (r − 1, t) for r ≥ 2, and (1, t) ∼ centre.
Occupancy. n_max = 1 with two units, so the full configuration space has
Initial state. The two units are placed on the outermost shell at (4, 0) and (4, 1).
Three update rules. First, strictly inward only with no rest: (r, t) → (r − 1, t) for r ≥ 2, and (1, t) → centre. Second, as the first but with the identity edge admitted. Third, as the first but with a one-way same-shell transport (r, t) → (r, (t + 1) mod 6) admitted.
Timing and tie-breaking. Updates are enumerated as sequential single hops, a transport being legal when the source is occupied and the target has room. Every legal successor is entered as an edge and no single choice is made, so what is constructed is a relation graph rather than a deterministic sequence of orbits.
Results
| Rule | \ | 𝒳_full\ | \ | Reach(n₀)\ | acyclic | forward-total | ΔΦ on a cycle | ||
|---|---|---|---|---|---|---|---|---|---|
| strictly inward only | 300 | 24 | yes | no (2 dead ends) | — | ||||
| identity admitted | 300 | 24 | no | yes | [0], length 1 | ||||
| same-shell admitted | 300 | 300 | no | yes | [0,0,0,0,0,0], length 6 |
For the first rule Φ(n₀) = 8, Φ_min = 1 and δ_min = 1, so N_max = ⌊(8 − 1)/1⌋ = 7; the longest directed orbit found by enumeration is likewise 7.
Remark one. That these two numbers agree is a result of enumeration and does not follow from the three quantities. Corollary 4.8 gives only an upper bound, and whether the bound is attained must be checked case by case. This serves as one instance of tightness, not as evidence for the theorem.
Remark two. Under the third rule the reachable set equals the full configuration space: circulation makes the whole space reachable. This is a by-product of that rule and not a conclusion needed here.
Remark three. No row is at once acyclic and forward-total, in accordance with Part C of Theorem 4.3.
Simple connectedness does not forbid combinatorial directed cycles (Kill 4)
Take the simplicial complex of a filled triangle: three vertices, three edges, one two-dimensional cell. It is contractible, so π₁ is trivial. Orient the three edges of its one-skeleton as a → b → c → a to obtain a directed three-cycle.
What simple connectedness obstructs is an orientation bundle, a topological object; a directed cycle is a combinatorial object given by the orientation of edges and is unaffected by the filling of the two-cell. The two do not imply one another. The tetrahedron is the same: its one-skeleton contains several directed three-cycles while the complex is contractible.
The coefficient of the cubic six-neighbour lattice
Closed form. For a unit normal n̂, let h(n̂) = max_i |n_i| be the exposure thickness of the six-neighbour lattice along that normal. Its spherical average is
⟨h⟩ = (6/π√2) arctan(1/√2) = 0.8311896360,
so the leading coefficient of the skin fraction and of the envelope fraction is
3⟨h⟩ = 2.4935689079.
Exact lattice counts. A cell is a bulk cell when all six of its face neighbours are also inside.
| R | N | skin | bulk | bulk fraction |
|---|---|---|---|---|
| 2.21 | 33 | 26 | 7 | 21.2121% |
| 5 | 515 | 222 | 293 | 56.8932% |
| 100 | 4,187,857 | 103,734 | 4,084,123 | 97.5230% |
Remark four. The R = 2.21 row must be distinguished from a large-R fit. Extrapolating a log-log fit over 5 ≤ R ≤ 120 down to R = O(1) gives a vanishing bulk fraction, while the exact count gives 21.21 per cent. A fitted expression must not be extrapolated outside its interval.
The influence-cone envelope
| R | t | t/R | \ | 𝒞_t ∩ B\ | /\ | B\ | fraction · R/t | implied b | |
|---|---|---|---|---|---|---|---|---|---|
| 160 | 1 | 0.00625 | 0.015520 | 2.48319 | −1.660 | ||||
| 40 | 1 | 0.02500 | 0.061316 | 2.45263 | −1.637 | ||||
| 80 | 2 | 0.02500 | 0.061324 | 2.45295 | −1.625 | ||||
| 160 | 4 | 0.02500 | 0.061307 | 2.45227 | −1.652 | ||||
| 80 | 4 | 0.05000 | 0.120576 | 2.41152 | −1.641 | ||||
| 120 | 6 | 0.05000 | 0.120507 | 2.41013 | −1.669 |
Writing
the six rows give implied values of b between −1.63 and −1.67, consistent across an eightfold range of t/R. The data are compatible with a quadratic correction of about −1.65; the extracted value still carries the O(1/R) discreteness error, so it is reported as an empirical coefficient and not as a determined constant.
The three rows sharing t/R = 0.025 differ by a relative spread of about 2.8 × 10⁻⁴, which is the O(1/R) lattice-discreteness effect and is not of the same origin as the finite-thickness quadratic term. The two must not be run together in one sentence.
Lattice dependence of the coefficient
The value 2.4936 is a joint product of the interior-cell criterion and six-neighbour adjacency, since h(n̂) = max_i |n_i| is precisely the exposure thickness of six-neighbour adjacency along the normal. The coefficient therefore varies with the definition of adjacency: a continuum shell one cell thick gives 3/R; eighteen-neighbour and twenty-six-neighbour adjacency and Voronoi cells all differ; and altering the interior criterion, for instance by requiring all neighbours rather than face neighbours only, changes it again.
> Only R⁻¹ is universal; the coefficient is not a constant of this framework.
Writing out its geometric origin allows a reader to change the lattice and recompute rather than take the number on trust.
Code and hashes
The scripts are published with the paper, with SHA-256 as follows. There are no dependencies beyond NumPy and NetworkX.
| Script | Corresponds to | SHA-256 |
|---|---|---|
exclusion.py | Appendix B, the 25-cell toy | aa9d3d9b9115b916c95e4391c9bc97f6ddad6c5e2614e3ad4ffce953c35b45de |
lattice.py | Appendix B, exact lattice counts and the closed-form coefficient | 1ea43fd3b20e13628377d017e31b8d42112a1f013b2ab5ca0acb5611fcb99726 |
cone.py | Appendix B, the influence-cone envelope fraction | 477678b33681648288102e4064e6b5cc3cb6627712696d78245046fd8bfc28f7 |
README.md | run instructions and statement of scope, Chinese | 38cfff31c90469b96e1e6b47f12365be5581fbe54b0e5859af83532bfcc4cfb4 |
README-en.md | the same, English | 4ad453681a05d8d04ee04d52bdf9e09e4bc0b881e151752fca96000a9558af04 |
Remark. The reproducibility commitment of this paper covers the three scripts above, being those on which the numerical values in the text actually depend. Computations along other routes taken during the writing do not enter the text and are therefore not published with it, so that no reader mistakes them for load-bearing.
Acknowledgements
The propositions of this paper passed through several rounds of independent review before completion, and several key corrections came from those reviews. Among them: the necessity of type separation; the layering of premises between the finite-total-function argument and uniform descent; and the distinction between the asymptotic and finite-size readings of the lattice coefficient. Errors that remain are the author's.
Metadata
Author Qin Han (秦汉). ORCID 0009-0009-9583-0018.
Series SAE Black Hole Series, Paper 2.
Date to be supplied.
Concept DOI 10.5281/zenodo.21499053 (resolves to the latest version). Version DOI assigned on publication.
Licence CC BY 4.0 (Creative Commons Attribution 4.0 International).
Reproducible material The three scripts of Appendix B together with both READMEs are published with the paper, each with SHA-256. Tested with Python 3.12.3, NumPy 2.4.4, NetworkX 3.6.1.
Note on this text This is an independent English rewrite rather than a translation of the Chinese text. Where the two differ in phrasing, the mathematical content, the numerals and the numbering of propositions are identical.
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