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Preprint · arXiv:2610.04420v1. Published on arXiv on 3 October 2026. The English text is reproduced unchanged from the original version on arXiv. Download the original PDF.

Seed thresholds and degree variance in heterogeneous bootstrap percolation with growing degrees

Aleksandr Rodionov Affiliation: Yandex, Saint Petersburg, Russia Affiliation: ORCID: 0009-0006-6710-923X Email: rexarrior@yandex.ru
Preprint — 29 September 2026
Abstract

We study bootstrap percolation with independent vertex thresholds taking values one and two, with threshold-one probability (1−c/d)/d(1-c/d)/d for fixed c>0c>0. The seed set is chosen uniformly among sets of a prescribed deterministic size, independently of the graph and thresholds. We prove threshold statements at fixed relative margins. For uniform simple graphs with prescribed nonnegative integer degrees of even sum and exact mean dd, assume maxi⁡|di−d|≤C​d\max_{i}|d_{i}-d|\leq C\sqrt{d} and c+1−vn≥κ>0c+1-v_{n}\geq\kappa>0, where vn=Var⁡(D)/dv_{n}=\operatorname{Var}(D)/d and C,κC,\kappa are fixed. When d→∞d\to\infty and d=o⁡(n1/7)d=o(n^{1/7}), the leading seed scale is n​(c+1−vn)2/(2​d4)n(c+1-v_{n})^{2}/(2d^{4}), without requiring a limit of vnv_{n}. At fixed relative margins below and above this scale, the final active set has size O⁡(n/d3)O(n/d^{3}) and n−o⁡(n)n-o(n), respectively, with high probability. A separate result for G⁡(n,d/n)G(n,d/n) holds when d→∞d\to\infty and d5/n→0d^{5}/n\to 0, and gives scale n​c2/(2​d4)nc^{2}/(2d^{4}). Thus regular and independent-edge graphs have different coefficients at the same asymptotic mean degree. Local exploration estimates yield explicit inactive remainders and survive conditioning on simplicity in the prescribed model. We also quantify the precision obstruction to static inclusion transfer and compute deterministic response-barrier corrections, without identifying a shrinking random critical window.

1 Model and main results

On a finite simple graph on [n]={1,…,n}[n]=\{1,\ldots,n\}, start from a seed set A0A_{0} and repeatedly activate each inactive vertex having at least RiR_{i} active neighbours. Activation is permanent; write A∞A_{\infty} for the final active set. Throughout, n→∞n\to\infty and logarithms are natural. For a fixed c>0c>0, the thresholds are mutually independent and independent of the graph, with

Pr⁡(Ri=1)=π=1−c/dd,Pr⁡(Ri=2)=1−π.\Pr(R_{i}=1)=\pi=\frac{1-c/d}{d},\qquad\Pr(R_{i}=2)=1-\pi. (1)

The seed set is independent of the graph and all thresholds and is uniform among subsets of a prescribed deterministic integer size a=an∈{0,…,n}a=a_{n}\in\{0,\ldots,n\}. Write α=a/n\alpha=a/n. All probability statements average over the graph, thresholds and seeds. With high probability means with probability tending to one along each sequence satisfying the stated hypotheses. A bound X=O⁡(fn)X=O(f_{n}) with high probability means that some fixed finite BB satisfies Pr⁡(X≤B​fn)→1\Pr(X\leq Bf_{n})\to 1.

1.1 Excess degree and the seed scale

For prescribed degrees let DD have the empirical degree distribution, let d=𝔼​Dd=\mathbb{E}D, and put vn=Var⁡(D)/dv_{n}=\operatorname{Var}(D)/d. We assume a fixed positive gap c+1−vn≥κ>0c+1-v_{n}\geq\kappa>0. The excess-degree identity and its deficit are

𝔼⁡[D⁡(D−1)]d=d−1+vn,b=c+1−vnd+c⁡(vn−1)d2.\frac{\mathbb{E}[D(D-1)]}{d}=d-1+v_{n},\qquad b=\frac{c+1-v_{n}}{d}+\frac{c(v_{n}-1)}{d^{2}}.

Thus b≍d−1b\asymp d^{-1} uniformly under the fixed parameter bounds. If additionally vn→vv_{n}\to v, the leading coefficient specializes to (c+1−v)2/2(c+1-v)^{2}/2. The main theorem does not require this convergence.

For regular degrees the remaining degree is d−1d-1: the edge used to reach the vertex is no longer available. For a Poisson degree law of mean dd, size bias followed by removal of the arrival edge leaves mean dd. This one-edge difference changes the deficit from (c+1)/d+O⁡(d−2)(c+1)/d+O(d^{-2}) to c/dc/d. The next response coefficient is K∼d2K\sim d^{2}, producing the seed scale b2/(2​K)b^{2}/(2K) and hence the two different leading coefficients. The theorems below justify this deterministic prediction.

For prescribed degrees we quantitatively refine the established exponential exploration at the shrinking bottleneck scale, with error probabilities sufficient for conditioning on simplicity. For independent edges we specialize the established independent-mark and maximal empirical-process arguments to the mixed response, obtaining the range d5/n→0d^{5}/n\to 0. Both arguments give terminal bounds at fixed relative margins.

The resulting regular/independent-edge separation rigorously realizes the prediction of the established response equations. The slow-degree supercritical overlap with finite-time approximation is recorded in Appendix B. Higher-moment refinements concern deterministic barriers, rather than the centre of a random critical window.

1.2 Threshold statements

Define the residual bounds

ℛP(n,d,C)=n[d 2−d+C​d+n−1/3],ℛE(n,d)=n[(1+d)e−d/2+d/n+n−1/3].\mathcal{R}_{\rm P}(n,d,C)=n\bigl[d\,2^{-d+C\sqrt{d}}+n^{-1/3}\bigr],\qquad\mathcal{R}_{\rm E}(n,d)=n\bigl[(1+d)e^{-d/2+d/n}+n^{-1/3}\bigr]. (2)
Theorem 1 (P: prescribed degrees).

Fix c>0c>0, C≥0C\geq 0, κ>0\kappa>0 and γ∈(0,1)\gamma\in(0,1). Let d1,…,dnd_{1},\ldots,d_{n} be nonnegative integers with even sum n​dnd, where d=n−1​∑idid=n^{-1}\sum_{i}d_{i} is the exact mean. Let DD have the empirical degree distribution, and assume

maxi⁡|di−d|≤C​d,vn=Var⁡(D)d,c+1−vn≥κ,\max_{i}|d_{i}-d|\leq C\sqrt{d},\qquad v_{n}=\frac{\operatorname{Var}(D)}{d},\qquad c+1-v_{n}\geq\kappa, (3)
d⟶∞,d=o⁡(n1/7).d\longrightarrow\infty,\qquad d=o(n^{1/7}). (4)

Set

b=1−π​𝔼⁡[D⁡(D−1)]d,K=(1−2​π)​𝔼​[D​(D−1)​(D−2)]d,A=b22​K.b=1-\pi\frac{\mathbb{E}[D(D-1)]}{d},\qquad K=(1-2\pi)\frac{\mathbb{E}[D(D-1)(D-2)]}{d},\qquad A=\frac{b^{2}}{2K}. (5)

For all sufficiently large nn, the degree sequence is graphical, 0<π<10<\pi<1, b>0b>0 and K>0K>0. On the uniform simple graph with these degrees, under the threshold and seed conventions above, there exist finite constants B−,B+B_{-},B_{+} depending only on c,C,κ,γc,C,\kappa,\gamma such that, for every sequence of prescribed deterministic seed sizes,

a≤(1−γ)​n​A\displaystyle a\leq(1-\gamma)nA ⟹Pr⁡(|A∞|≤B−​n/d3)⟶1,\displaystyle\ \Longrightarrow\quad\Pr\bigl(|A_{\infty}|\leq B_{-}n/d^{3}\bigr)\longrightarrow 1, (6)
a≥(1+γ)​n​A\displaystyle a\geq(1+\gamma)nA ⟹Pr⁡(n−|A∞|≤B+​ℛP​(n,d,C))⟶1.\displaystyle\ \Longrightarrow\quad\Pr\bigl(n-|A_{\infty}|\leq B_{+}\mathcal{R}_{\rm P}(n,d,C)\bigr)\longrightarrow 1. (7)

Here and below an inequality on ana_{n} is required eventually. No convergence of vnv_{n} is assumed.

Theorem 2 (E: independent edges).

Fix c>0c>0 and γ∈(0,1)\gamma\in(0,1), and let

d⟶∞,d5n⟶0.d\longrightarrow\infty,\qquad\frac{d^{5}}{n}\longrightarrow 0. (8)

Take G∼G⁡(n,d/n)G\sim G(n,d/n) with the threshold and seed conventions above, and put AE=c2/(2​d4)A_{\rm E}=c^{2}/(2d^{4}) and aE=n​AEa_{\rm E}=nA_{\rm E}. There exist finite constants B−E,B+EB_{-}^{\rm E},B_{+}^{\rm E} depending only on c,γc,\gamma such that, for every sequence of prescribed deterministic seed sizes,

a≤(1−γ)​aE\displaystyle a\leq(1-\gamma)a_{\rm E} ⟹Pr⁡(|A∞|≤B−E​n/d3)⟶1,\displaystyle\ \Longrightarrow\quad\Pr\bigl(|A_{\infty}|\leq B_{-}^{\rm E}n/d^{3}\bigr)\longrightarrow 1, (9)
a≥(1+γ)​aE\displaystyle a\geq(1+\gamma)a_{\rm E} ⟹Pr⁡(n−|A∞|≤B+E​ℛE​(n,d))⟶1.\displaystyle\ \Longrightarrow\quad\Pr\bigl(n-|A_{\infty}|\leq B_{+}^{\rm E}\mathcal{R}_{\rm E}(n,d)\bigr)\longrightarrow 1. (10)

This theorem treats the independent-edge model separately, without the prescribed-degree assumptions of Theorem 1. Here d=n​pd=np parametrizes the edge probability, and the exact expected degree is (n−1)​d/n(n-1)d/n.

Both residual bounds are o⁡(n)o(n) in their respective ranges, so the supercritical conclusions imply |A∞|/n→1|A_{\infty}|/n\to 1 in probability. They do not assert full activation or a shrinking critical window. The seed-size quantifiers concern prescribed sizes and independent uniform seeds, not seeds selected after observing graph or thresholds.

Constants.

The model parameters c,C,κc,C,\kappa and relative margin γ\gamma are fixed whenever applicable. Constants in the prescribed-degree probability bounds may depend only on c,C,κ,γc,C,\kappa,\gamma; those in the independent-edge bounds may depend only on c,γc,\gamma. Constants in the logarithmic corollary may additionally depend on its fixed K0K_{0}. Unspecified constants may vary between estimates, while the model parameters remain fixed. The index from which an asymptotic estimate holds may depend on the chosen sequence and its convergence rates; it need not be uniform over those sequences. In the abstract deterministic barrier lemma, constants may also depend on its uniform comparison and derivative bounds and its fixed local interval. None of these statements permits γ→0\gamma\to 0 or κ→0\kappa\to 0.

Lemma 3 (Empirical moments and transfer at fixed margins).

Under (3), with fixed c,C,κc,C,\kappa and d→∞d\to\infty, let qn=c+1−vnq_{n}=c+1-v_{n} and A0,n=qn2/(2​d4)A_{0,n}=q_{n}^{2}/(2d^{4}). For b,K,Ab,K,A in (5), uniformly over these empirical laws,

b=qnd+c⁡(vn−1)d2,K=d2​(1+O⁡(d−1)),A=qn22​d4​(1+O⁡(d−1)).b=\frac{q_{n}}{d}+\frac{c(v_{n}-1)}{d^{2}},\qquad K=d^{2}\bigl(1+O(d^{-1})\bigr),\qquad A=\frac{q_{n}^{2}}{2d^{4}}\bigl(1+O(d^{-1})\bigr). (11)

Thus (6) and (7) remain valid with A0,nA_{0,n} in place of AA, for each fixed relative margin (with possibly changed constants). If in addition vn→vv_{n}\to v, then v<c+1v<c+1 and

n​A∼n​(c+1−v)22​d4,nA\sim\frac{n(c+1-v)^{2}}{2d^{4}}, (12)

and that limiting expression may likewise replace n​AnA in the fixed-margin conclusions. The deterministic estimates in (11) do not require a relation between nn and dd; the probability conclusions retain (4).

Corollary 4 (Regular separation).

Fix c>0c>0. Let d=dnd=d_{n} be integer, n​dnd even, and assume d→∞d\to\infty and d=o⁡(n1/7)d=o(n^{1/7}). Compare the uniform simple dd-regular graph and G⁡(n,d/n)G(n,d/n) under the same threshold and seed conventions. Their leading seed scales are

tR=(c+1)2​n2​d4,tE=c2​n2​d4,tRtE=(c+1)2c2.t_{\rm R}=\frac{(c+1)^{2}n}{2d^{4}},\qquad t_{\rm E}=\frac{c^{2}n}{2d^{4}},\qquad\frac{t_{\rm R}}{t_{\rm E}}=\frac{(c+1)^{2}}{c^{2}}.

Precisely, for every fixed γ∈(0,1)\gamma\in(0,1), seeds below (1−γ)​tR(1-\gamma)t_{\rm R} give O⁡(n/d3)O(n/d^{3}) final active vertices in the regular model, whereas seeds above (1+γ)​tR(1+\gamma)t_{\rm R} leave O​(ℛP​(n,d,0))O(\mathcal{R}_{\rm P}(n,d,0)) inactive vertices, with high probability. The corresponding E statements hold with tEt_{\rm E} and ℛE​(n,d)\mathcal{R}_{\rm E}(n,d). For every fixed c2/2<λ<(c+1)2/2c^{2}/2<\lambda<(c+1)^{2}/2 and deterministic integer a∼λ​n/d4a\sim\lambda n/d^{4},

|A∞R|=O(n/d3),n−|A∞E|=O(ℛE(n,d))=o(n)with high probability.|A_{\infty}^{\rm R}|=O(n/d^{3}),\qquad n-|A_{\infty}^{\rm E}|=O(\mathcal{R}_{\rm E}(n,d))=o(n)\quad\hbox{with high probability}.

If also d≥K0​log⁡nd\geq K_{0}\log n eventually for fixed K0>2/3K_{0}>2/3, the E residual in this separation is O⁡(n2/3)O(n^{2/3}) with high probability. The comparison uses the same asymptotic mean degree; the exact means are dd and d−d/nd-d/n, respectively.

The proofs of Lemma 3 and Corollary 4 are given in Section 2. That section also records a sufficient logarithmic condition for an O⁡(n2/3)O(n^{2/3}) inactive remainder and an example with two degree values.

1.3 Relation to earlier work

Section VI, equation (24) of the arXiv:1003.5583v2 (2010) version of Baxter et al. (2010) gives the distributional threshold equation used here. Set its damage parameter to one and its threshold probabilities at zero, one, and two to α,(1−α)​π,(1−α)​(1−π)\alpha,(1-\alpha)\pi,(1-\alpha)(1-\pi). The coefficients in (5) are Taylor coefficients of this established equation. We use the equation and its formal expansion as existing tools; our contribution is the quantitative terminal control specified above.

For independent edges, Janson et al. (2012) use independent Bernoulli marks, and Ballen and Guha (2015) allow nonuniform thresholds. The latter’s exact binomial response gives our mixed drift. Their Theorem 1 assumes a fixed positive gap β\beta through d​ζ1≤1−βd\zeta_{1}\leq 1-\beta, writing dd for their expected-degree parameter η​ϕ\eta\phi. In our regime d​π=1−c/dd\pi=1-c/d, this gap vanishes, so that theorem does not directly apply. We apply the distribution-free forward/reverse empirical-process proof in Lemmas 7.2–7.3 of arXiv:1012.3535v2 to the mixed activation-time CDF, localize the early horizon and use dyadic error budgets. This is a specialization of established arguments, rather than a new exploration or maximal inequality.

For prescribed degrees, Amini (2010) requires a finite limiting mean and a bounded empirical second moment. Lelarge (2012) also treats independent random thresholds on prescribed-degree graphs, including uniform simple graphs. Condition 1 and Theorem 10 in the arXiv:1012.2062v4 (2011) version assume a fixed limiting degree law with finite mean and ∑idi2=O⁡(n)\sum_{i}d_{i}^{2}=O(n); these assumptions exclude our growing-degree sequences. The op​(n)o_{p}(n) exploration approximation in its proof does not by itself resolve our bottleneck of order n/d3n/d^{3}. Condition 1.1 in the arXiv:2103.00357v2 (2022) version of Amini et al. (2023) requires a limiting degree/threshold law and uniform exponential moments. These hypotheses fail in (3). We use the exponential half-edge exploration described by these authors. Our quantitative control includes local loss variance, stopped short-time predictable quadratic variation, the fixed-size seed mean and time interpolation. Garetto et al. (2016) already discuss degree heterogeneity and compare regular and two-level examples; their condition excluding one-edge activation and their homogeneous prescribed-degree calculation do not directly give our mixture.

Janson (2009) includes fixed-size initial sets and a critical-window result for fixed regular degree and common threshold. Prescribed seed size is therefore already covered in the literature. A different comparison concerns finite-time approximation: Rossi et al. (2019) develop quantitative finite-time coupling and concentration estimates for threshold dynamics (Sections 4.2–4.3.1 of the 2017 accepted manuscript). We prove below the excess-degree version needed here. Under our prescribed-degree assumptions and fixed supercritical seed margin, this adaptation yields an O⁡(n2/3)O(n^{2/3}) inactive remainder when d​log⁡d=o⁡(log⁡n)d\log d=o(\log n); see Appendix B. This uses the excess-degree offspring law, joint concentration of pairing and labels, and conditioning on simplicity. In the comparison established here, the subcritical terminal upper bound still requires control of activation after the certified finite horizon. The adaptation neither covers our full degree range nor proves the independent-edge counterpart.

For fixed degree dd and a common threshold 2≤k≤d−12\leq k\leq d-1, Balogh and Pittel (2007, Theorems 1–3) establish threshold and window estimates, including deterministic initial sets. Their equation (3) and equations (17)–(20) already express the threshold through the infimum of a deterministic response ratio. At the level of the deterministic response, replacing their binomial tail by the mixture of the tails for thresholds one and two gives our regular response; this substitution does not itself extend their probability theorems. Their passage from configurations to simple graphs uses a simplicity probability bounded away from zero for fixed dd; it does not directly supply the uniform conditioning argument needed here.

Organization.

Section 2 proves the consequences stated above, gives further examples, and establishes the common deterministic barrier. Sections 3 and 4 connect it to the respective explorations and concentration bounds; the prescribed-degree proof then conditions on simplicity. Section 5 explains the precision obstruction to static inclusion transfer. Section 6 derives finite-degree and higher-moment corrections, and Section 7 records the remaining limits. The appendices supply the local concentration estimates and the slow-degree comparison with finite-time approximation.

2 Consequences and deterministic estimates

2.1 Empirical moments and consequences

Proof of Lemma 3.

Write μ3=𝔼⁡[(D−d)3]\mu_{3}=\mathbb{E}[(D-d)^{3}]. The deviation bound gives 0≤vn≤C20\leq v_{n}\leq C^{2} and |μ3|≤C​d​𝔼​[(D−d)2]=O⁡(d3/2)|\mu_{3}|\leq C\sqrt{d}\,\mathbb{E}[(D-d)^{2}]=O(d^{3/2}). The exact factorial-moment identities give the displayed formula for bb and

K=(1−2​π)​[d2+(3​vn−3)​d+2−3​vn+μ3d].K=(1-2\pi)\left[d^{2}+(3v_{n}-3)d+2-3v_{n}+\frac{\mu_{3}}{d}\right].

Consequently K/d2=1+O⁡(d−1)K/d^{2}=1+O(d^{-1}) and, since qn≥κq_{n}\geq\kappa, b=(qn/d)​(1+O⁡(d−1))b=(q_{n}/d)(1+O(d^{-1})). This proves (11). For any positive densities Tn,AnT_{n},A_{n} with Tn/An→1T_{n}/A_{n}\to 1 and fixed γ∈(0,1)\gamma\in(0,1), eventually

(1−γ)​Tn≤(1−γ/2)​An,(1+γ)​Tn≥(1+γ/2)​An.(1-\gamma)T_{n}\leq(1-\gamma/2)A_{n},\qquad(1+\gamma)T_{n}\geq(1+\gamma/2)A_{n}.

Apply the appropriate theorem with margin γ/2\gamma/2. If vn→vv_{n}\to v, the fixed gap gives c+1−v≥κc+1-v\geq\kappa, and the same argument proves the limiting specialization. ∎

Integer seed sizes.

In both (4) and (8), n/d4→∞n/d^{4}\to\infty. Thus rounding a size of order n/d4n/d^{4} changes it by a relative o⁡(1)o(1). More precisely, for any theorem centre A⋆≍d−4A_{\star}\asymp d^{-4}, ⌊(1−γ)​n​A⋆⌋\lfloor(1-\gamma)nA_{\star}\rfloor satisfies its subcritical inequality and ⌈(1+γ)​n​A⋆⌉\lceil(1+\gamma)nA_{\star}\rceil satisfies its supercritical inequality. The reference size ⌈(1+γ/2)​n​A⋆⌉\lceil(1+\gamma/2)nA_{\star}\rceil is no larger than every permitted supercritical size for all sufficiently large nn. Uniform seeds of all prescribed sizes can be coupled as initial segments of one uniform permutation independent of graph and thresholds. Monotonicity of bootstrap closure then transfers a bound from a reference size to each permitted smaller or larger prescribed size.

Corollary 5 (A sufficient logarithmic condition).

In the supercritical conclusion of Theorem 1, suppose also d≥K0​log⁡nd\geq K_{0}\log n eventually for some fixed K0>1/(3​log⁡2)K_{0}>1/(3\log 2). Then n−|A∞|=O⁡(n2/3)n-|A_{\infty}|=O(n^{2/3}) with high probability. In the supercritical conclusion of Theorem 2, the same conclusion holds if d≥K0​log⁡nd\geq K_{0}\log n eventually for some fixed K0>2/3K_{0}>2/3. These are sufficient conditions, not necessary conditions or optimal constants; the boundary equalities are not asserted.

Proof.

For P the function f⁡(x)=x​log⁡2−C​x​log⁡2−log⁡xf(x)=x\log 2-C\sqrt{x}\log 2-\log x is increasing for all sufficiently large xx. Hence

f⁡(d)−13​log⁡n≥(K0​log​2−13)​log​n−O⁡(log⁡n)−O⁡(log⁡log⁡n)⟶∞.f(d)-\tfrac{1}{3}\log n\geq(K_{0}\log 2-\tfrac{1}{3})\log n-O(\sqrt{\log n})-O(\log\log n)\longrightarrow\infty.

It follows that d2−d+C​d=o(n−1/3)d2^{-d+C\sqrt{d}}=o(n^{-1/3}). For E, g⁡(x)=x/2−log⁡(1+x)g(x)=x/2-\log(1+x) is eventually increasing and d/n=o⁡(1)d/n=o(1). Therefore

g⁡(d)−13​log⁡n−d/n≥(K0/2−13)​log⁡n−O⁡(log⁡log⁡n)−o⁡(1)⟶∞,g(d)-\tfrac{1}{3}\log n-d/n\geq(K_{0}/2-\tfrac{1}{3})\log n-O(\log\log n)-o(1)\longrightarrow\infty,

so (1+d)e−d/2+d/n=o(n−1/3)(1+d)e^{-d/2+d/n}=o(n^{-1/3}). Insert these estimates into (2) and the corresponding supercritical theorem. ∎

Proof of Corollary 4.

For the regular model C=vn=0C=v_{n}=0 and

bR=c+1d−cd2,KR=(1−2​π)​(d−1)​(d−2),n​AR∼tR.b_{\rm R}=\frac{c+1}{d}-\frac{c}{d^{2}},\qquad K_{\rm R}=(1-2\pi)(d-1)(d-2),\qquad nA_{\rm R}\sim t_{\rm R}.

Theorem 1 and Lemma 3 give the regular statements. The common range implies (8), since

d5n=(dn1/7)5n−2/7⟶0.\frac{d^{5}}{n}=\left(\frac{d}{n^{1/7}}\right)^{5}n^{-2/7}\longrightarrow 0.

Thus Theorem 2 applies as well. Put L=c2/2L=c^{2}/2, U=(c+1)2/2U=(c+1)^{2}/2 and

γ∗=14​min⁡{1,λ/L−1,1−λ/U}>0.\gamma_{*}=\frac{1}{4}\min\{1,\lambda/L-1,1-\lambda/U\}>0.

The ratios a/tE→λ/La/t_{\rm E}\to\lambda/L and a/(n​AR)→λ/Ua/(nA_{\rm R})\to\lambda/U place the seeds on opposite sides with margin γ∗\gamma_{*}. The theorem bounds and a union bound give the joint conclusion. Independence between the two graphs is not needed: one may use any coupling of their laws, with common threshold labels and a uniform seed permutation independent of the graph pair. Rounding λ​n/d4\lambda n/d^{4} is harmless by n/d4→∞n/d^{4}\to\infty. The last assertion follows from Corollary 5. ∎

Corollary 6 (Two degree values).

Fix c>0c>0, κ>0\kappa>0 and γ∈(0,1)\gamma\in(0,1). Let nn be even, s≥0s\geq 0, and let d−s,d+sd-s,d+s be nonnegative integers with n​dnd even. Assign degree d−sd-s to half the vertices and d+sd+s to the other half. Assume d→∞d\to\infty, d=o⁡(n1/7)d=o(n^{1/7}), and

vn=s2d,qn=c+1−vn≥κ.v_{n}=\frac{s^{2}}{d},\qquad q_{n}=c+1-v_{n}\geq\kappa.

Set t2,n=n​qn2/(2​d4)t_{2,n}=nq_{n}^{2}/(2d^{4}) and C2=c+1C_{2}=\sqrt{c+1}. The sequence is graphical eventually. For the uniform simple graph with these degrees and the stated independent threshold and seed model,

a≤(1−γ)​t2,n⟹|A∞|=O⁡(n/d3)with high probability,a≥(1+γ)​t2,n⟹n−|A∞|=O⁡(ℛP​(n,d,C2))with high probability.\begin{split}a\leq(1-\gamma)t_{2,n}&\ \Longrightarrow\quad|A_{\infty}|=O(n/d^{3})\quad\hbox{with high probability},\\ a\geq(1+\gamma)t_{2,n}&\ \Longrightarrow\quad n-|A_{\infty}|=O(\mathcal{R}_{\rm P}(n,d,C_{2}))\quad\hbox{with high probability}.\end{split}

If d≥K0​log⁡nd\geq K_{0}\log n eventually for fixed K0>1/(3​log⁡2)K_{0}>1/(3\log 2), the supercritical residual is O⁡(n2/3)O(n^{2/3}) with high probability. If additionally vn→v<c+1v_{n}\to v<c+1, then t2,nt_{2,n} may be replaced in these fixed-margin statements by n​(c+1−v)2/(2​d4)n(c+1-v)^{2}/(2d^{4}).

Proof.

The empirical mean is exactly dd, its variance is s2s^{2}, and its third central moment is zero. The gap implies s≤c+1​ds\leq\sqrt{c+1}\sqrt{d}, so the P deviation condition holds with fixed C2C_{2}. In particular,

b=qnd+c⁡(vn−1)d2,K=(1−2​π)​[d2+(3​vn−3)​d+2−3​vn].b=\frac{q_{n}}{d}+\frac{c(v_{n}-1)}{d^{2}},\qquad K=(1-2\pi)[d^{2}+(3v_{n}-3)d+2-3v_{n}].

Apply Theorem 1, Lemma 3, and Corollary 5. ∎

The conditions concern the two degrees themselves: d,sd,s may both be half-integers, and even nn alone does not ensure even n​dnd. For a concrete limiting-variance example, fix 0≤v<c+10\leq v<c+1, take integer d→∞d\to\infty and even nn in the stated range, and set s=⌊v​d⌋s=\lfloor\sqrt{vd}\rfloor. Then the degrees are nonnegative integers eventually, n​dnd is even, and

0≤v−vn≤2​v/d,vn⟶v.0\leq v-v_{n}\leq 2\sqrt{v/d},\qquad v_{n}\longrightarrow v.

A fixed positive gap follows, and the limiting specialization applies. For finite-degree corrections the actual vn=s2/dv_{n}=s^{2}/d must still be retained; this example supplies no o⁡(d−1)o(d^{-1}) rate for vn−vv_{n}-v. The case s=0s=0 is regular. The agreement of a leading coefficient at the formal variance value v=1v=1 does not make the independent-edge model a special case of the prescribed maximum-deviation hypothesis.

2.2 A common deterministic barrier

The two models share the same local mechanism: an unseeded response FF with F′​(0)=1−bF^{\prime}(0)=1-b and F′′​(0)=KF^{\prime\prime}(0)=K produces a barrier of order b2/(2​K)b^{2}/(2K). The next lemma controls this barrier and the drift beyond it; the probabilistic arguments will then compare the exploration queues with that drift.

Lemma 7 (A small-deficit response barrier).

Let d→∞d\to\infty and let F:[0,1/2]→[0,1)F:[0,1/2]\to[0,1) be nondecreasing, with F⁡(0)=0F(0)=0. Suppose that FF is C3C^{3} on [0,ε/d][0,\varepsilon/d] for a fixed ε>0\varepsilon>0, with one-sided endpoint derivatives, and that

F′​(0)=1−b,F′′​(0)=K,b∗/d≤b≤b∗/d,K∗​d2≤K≤K∗​d2,F^{\prime}(0)=1-b,\quad F^{\prime\prime}(0)=K,\quad b_{*}/d\leq b\leq b^{*}/d,\quad K_{*}d^{2}\leq K\leq K^{*}d^{2},
F′′≥K/2,|F′′′|≤C3d3(0≤z≤ε/d).F^{\prime\prime}\geq K/2,\quad|F^{\prime\prime\prime}|\leq C_{3}d^{3}\quad(0\leq z\leq\varepsilon/d).

Here b∗,b∗,K∗,K∗,C3b_{*},b^{*},K_{*},K^{*},C_{3} are fixed positive constants. Assume supξ≤z≤1/2(1−F⁡(z))=o⁡(1)\sup_{\xi\leq z\leq 1/2}(1-F(z))=o(1) for each fixed ξ∈(0,1/2)\xi\in(0,1/2). Put A=b2/(2​K)A=b^{2}/(2K), z0=b/Kz_{0}=b/K and hα​(z)=α+(1−α)​F​(z)−zh_{\alpha}(z)=\alpha+(1-\alpha)F(z)-z. Choose any fixed L>8​b∗/K∗L>8b^{*}/K_{*}. For every fixed η∈(0,1)\eta\in(0,1), if α±=(1±η)​A+o⁡(A)\alpha_{\pm}=(1\pm\eta)A+o(A), then, eventually, for a fixed kη>0k_{\eta}>0,

hα+(z)≥kη{d−4,0≤z≤L/d3,d2​z2,L/d3≤z≤ε/d,1,ε/d≤z≤1/2,hα−(z0)≤−ηA/2.h_{\alpha_{+}}(z)\geq k_{\eta}\begin{cases}d^{-4},&0\leq z\leq L/d^{3},\\ d^{2}z^{2},&L/d^{3}\leq z\leq\varepsilon/d,\\ 1,&\varepsilon/d\leq z\leq 1/2,\end{cases}\qquad h_{\alpha_{-}}(z_{0})\leq-\eta A/2. (13)

The constants depend only on the displayed fixed bounds, LL and η\eta. Moreover R=(z−F)/(1−F)R=(z-F)/(1-F) has a unique global maximum on [0,1/2][0,1/2], attained in (0,8​b/K)(0,8b/K), of value A+o⁡(A)A+o(A).

Proof.

Uniformly on [0,L/d3][0,L/d^{3}], for α=O⁡(A)\alpha=O(A),

hα​(z)=α−A+K2​(z−z0)2+O⁡(d3​z3+α​F​(z)).h_{\alpha}(z)=\alpha-A+\frac{K}{2}(z-z_{0})^{2}+O(d^{3}z^{3}+\alpha F(z)). (14)

Indeed Taylor expansion also gives F⁡(z)=O⁡(d−3)F(z)=O(d^{-3}) there, so the two remainder terms are O⁡(d−6)O(d^{-6}) and O⁡(d−7)O(d^{-7}), both o⁡(A)o(A). This proves the early and negative margins. For z≥L/d3≥8​b/Kz\geq L/d^{3}\geq 8b/K and z≤ε/dz\leq\varepsilon/d,

F⁡(z)−z≥−b​z+K​z2/4≥K​z2/8.F(z)-z\geq-bz+Kz^{2}/4\geq Kz^{2}/8.

Thus F⁡(ε/d)≥q0F(\varepsilon/d)\geq q_{0} eventually for some fixed 0<q0≤1/40<q_{0}\leq 1/4. On [ε/d,q0/2][\varepsilon/d,q_{0}/2] monotonicity gives F−z≥q0/2F-z\geq q_{0}/2; on [q0/2,1/2][q_{0}/2,1/2] the tail hypothesis gives F−z≥1/4F-z\geq 1/4 eventually. Since hα=F−z+α⁡(1−F)≥F−zh_{\alpha}=F-z+\alpha(1-F)\geq F-z for α≥0\alpha\geq 0, this proves the remaining margins.

For B=1−FB=1-F, on [0,8​b/K][0,8b/K],

R′=g/B2,g=B−(1−z)​F′,g′=−(1−z)​F′′.R^{\prime}=g/B^{2},\quad g=B-(1-z)F^{\prime},\quad g^{\prime}=-(1-z)F^{\prime\prime}.

Here gg is strictly decreasing, g⁡(0)=bg(0)=b and g⁡(8​b/K)=−7​b+O⁡(d−3)<0g(8b/K)=-7b+O(d^{-3})<0. There is a unique early maximum. The preceding middle and late argument, starting at 8​b/K8b/K, gives F−z>0F-z>0 everywhere outside that interval, so R<0R<0 there. Inside it R=b​z−K​z2/2+o⁡(A)R=bz-Kz^{2}/2+o(A) uniformly; its maximum is A+o⁡(A)>0A+o(A)>0. All perturbations o⁡(A)o(A) are absorbed by the fixed margin. ∎

Verification for the two responses.

For the prescribed empirical law define, with y=1−zy=1-z,

Bk​(z)=yk−1+(1−π)​(k−1)​z​yk−2,FP​(z)=1−1d​𝔼​[D​BD​(z)].B_{k}(z)=y^{k-1}+(1-\pi)(k-1)zy^{k-2},\qquad F_{\rm P}(z)=1-\frac{1}{d}\mathbb{E}[DB_{D}(z)].

For independent edges define

FE​(z)=1−e−d​z​[1+(1−π)​d​z].F_{\rm E}(z)=1-e^{-dz}[1+(1-\pi)dz].

The P verification uses only (3), fixed c,C,κc,C,\kappa and d→∞d\to\infty. Lemma 3 gives its b,K,Ab,K,A. Eventually δ=mini⁡di≥7\delta=\min_{i}d_{i}\geq 7, Δ=maxi⁡di≍d\Delta=\max_{i}d_{i}\asymp d. For Fk=1−BkF_{k}=1-B_{k} and 1≤j≤51\leq j\leq 5,

Fk(j)​(z)=(−1)j+1​(k−1)j​yk−2−j​{[1−j⁡(1−π)]​y+(1−π)​(k−1−j)​z}.F_{k}^{(j)}(z)=(-1)^{j+1}(k-1)_{j}y^{k-2-j}\{[1-j(1-\pi)]y+(1-\pi)(k-1-j)z\}.

In particular Fk′≥0F_{k}^{\prime}\geq 0 and

Fk′′=(k−1)​(k−2)​yk−4​{(1−2​π)​y−(1−π)​(k−3)​z}.F_{k}^{\prime\prime}=(k-1)(k-2)y^{k-4}\{(1-2\pi)y-(1-\pi)(k-3)z\}.

For E, for 1≤j≤51\leq j\leq 5,

FE(j)​(z)=(−1)j+1​dj​e−d​z​[1−j⁡(1−π)+(1−π)​d​z].F_{\rm E}^{(j)}(z)=(-1)^{j+1}d^{j}e^{-dz}[1-j(1-\pi)+(1-\pi)dz].

It has b=c/db=c/d, K=(1−2​π)​d2K=(1-2\pi)d^{2} and Aquad=b2/(2​K)=AE​(1+O⁡(d−1))A^{\rm quad}=b^{2}/(2K)=A_{\rm E}(1+O(d^{-1})). Both responses are nondecreasing and strictly below one on [0,1/2][0,1/2]. For a sufficiently small fixed ε>0\varepsilon>0 the formulas imply F′′≥K/2F^{\prime\prime}\geq K/2 and |F(j)|=O⁡(dj)|F^{(j)}|=O(d^{j}), 2≤j≤52\leq j\leq 5, on [0,ε/d][0,\varepsilon/d]. For P, k/d=1+O(d−1/2)k/d=1+O(d^{-1/2}) uniformly, so the ratio of each second derivative to its value at zero is at least 1/21/2 for small ε\varepsilon. For E its ratio is e−d​z​[1−(1−π)​d​z/(1−2​π)]e^{-dz}[1-(1-\pi)dz/(1-2\pi)], with the same property. For each fixed ξ>0\xi>0 the tail bounds are

1−FP(z)≤(1+Δ)(1−ξ)δ−2,1−FE(z)≤(1+d)e−d​ξ(ξ≤z≤1/2).1-F_{\rm P}(z)\leq(1+\Delta)(1-\xi)^{\delta-2},\qquad 1-F_{\rm E}(z)\leq(1+d)e^{-d\xi}\quad(\xi\leq z\leq 1/2).

Thus Lemma 7 applies to both responses without a relation between nn and dd. The same formulas give F′=O⁡(1)F^{\prime}=O(1) on each fixed early interval [0,L/d3][0,L/d^{3}].

3 Proof for prescribed degrees

Write δ=mini⁡di\delta=\min_{i}d_{i}, Δ=maxi⁡di\Delta=\max_{i}d_{i}, and take nn large enough that δ≥4\delta\geq 4 and 0<π<10<\pi<1. All constants below depend only on the fixed parameters of Theorem 1. Put M=∑idi=n​dM=\sum_{i}d_{i}=nd. We first work with a uniform pairing of the MM labelled half-edges, counting edges with multiplicity. We compare the active queue with its deterministic drift, use concentration to locate stopping or passage, and then bound the final number of active or inactive vertices. Finally, we condition on simplicity and check that the failure probabilities remain o⁡(1)o(1).

Response and deterministic margins.

Use F=FPF=F_{\rm P} from Section 2.2, B=1−FB=1-F, M=n​dM=nd and hα=α+(1−α)​F−zh_{\alpha}=\alpha+(1-\alpha)F-z. Lemma 3 gives b≍d−1b\asymp d^{-1}, K≍d2K\asymp d^{2} and A≍d−4A\asymp d^{-4}; the present degree range gives n​A→∞nA\to\infty. Take

a−=⌊(1−γ)​n​A⌋,a+=⌈(1+γ/2)​n​A⌉,α±=a±/n.a_{-}=\lfloor(1-\gamma)nA\rfloor,\qquad a_{+}=\lceil(1+\gamma/2)nA\rceil,\qquad\alpha_{\pm}=a_{\pm}/n.

Their rounding errors are o⁡(A)o(A). Choose LL as in Lemma 7 and apply it with margins γ\gamma and γ/2\gamma/2 respectively. Put η=ε\eta=\varepsilon, u=−log⁡(1−z)u=-\log(1-z) and Dα​(u)=M⁡(1−z)​hα​(z)D_{\alpha}(u)=M(1-z)h_{\alpha}(z). Since 1/2≤1−z≤11/2\leq 1-z\leq 1, for a sufficiently small fixed k>0k>0,

Dα+(u)≥{k​n/d3,0≤z≤L/d3,k​n​d3​z2,L/d3≤z≤η/d,k​n​d,η/d≤z≤1/2,Dα−(u∗)≤−kn/d3,u∗=−log(1−b/K).D_{\alpha_{+}}(u)\geq\begin{cases}kn/d^{3},&0\leq z\leq L/d^{3},\\ knd^{3}z^{2},&L/d^{3}\leq z\leq\eta/d,\\ knd,&\eta/d\leq z\leq 1/2,\end{cases}\qquad D_{\alpha_{-}}(u_{*})\leq-kn/d^{3},\quad u_{*}=-\log(1-b/K). (15)

Exploration and stopping convention.

Give every original half-edge an independent rate-one exponential clock, independently of the seeds and thresholds. Reserve one active end, without inspecting its future clock, and pair it to the first ringing unreserved end. Record a mark at the partner vertex, activate that vertex if its threshold is reached, and reserve the next active end. Use only revealed information to choose a reserved end. Stop at time τ\tau when no active end remains after a pairing. Complete all remaining pairs uniformly. By exponential memorylessness each exposed partner is uniform among the other remaining ends. Induction on the number of remaining ends therefore gives a uniform full pairing conditional on every seed and threshold assignment, so this pairing is independent of these assignments.

Every activation is justified by exposed edges from active vertices. At stopping all ends of active vertices have been explored; the remaining pairs join inactive vertices, each of which has received fewer than its threshold many marks from active vertices. The final set is therefore closed under the activation rule, and is exactly the bootstrap closure. In particular completion adds no activations.

Let Xi​(u)X_{i}(u) count original clocks at vertex ii expiring by uu, including latent clocks of removed ends, and set

H(u)=∑i∉A0(di−Xi(u))𝟏{Xi(u)<Ri}.H(u)=\sum_{i\notin A_{0}}(d_{i}-X_{i}(u))\mathbf{1}_{\{X_{i}(u)<R_{i}\}}.

Up to and including τ\tau, this is the actual number of inactive ends: before activation no end at that vertex was manually removed, and after activation its original-clock count stays at least its threshold. The formula remains a latent process after τ\tau, without implying any further real activation. Its unconditional mean is exactly

H¯​(u)=(1−α)​M​e−u​B​(1−e−u),M​e−2​u−H¯​(u)=Dα​(u).\bar{H}(u)=(1-\alpha)Me^{-u}B(1-e^{-u}),\qquad Me^{-2u}-\bar{H}(u)=D_{\alpha}(u). (16)

Let WW count unreserved ends, initially W⁡(0)=M−1W(0)=M-1. Each pairing decreases WW by two, with a fictitious final reservation if no active end is available. Thus the bookkeeping value of WW at τ\tau is one less than the actual remaining count, and

Q⁡(u):=W⁡(u)−H⁡(u)≥0(u<τ),Q⁡(τ)=−1.Q(u):=W(u)-H(u)\geq 0\quad(u<\tau),\qquad Q(\tau)=-1. (17)

All queue comparisons below include this terminal convention.

Local passage estimate.

Put U=log⁡2U=\log 2. The following estimate compares the queue with the three drift scales in (15).

Lemma 8 (Local concentration of the active queue).

Under the hypotheses of Theorem 1, consider the configuration model exploration just defined with either reference size a−a_{-} or a+a_{+}. Let k,L,ηk,L,\eta be as in (15). There are constants C2,k2>0C_{2},k_{2}>0, depending only on c,C,κ,γc,C,\kappa,\gamma, such that, except on an event of probability at most

C2(1+d2)(1+logd)exp(−k2n/d5),C_{2}(1+d^{2})(1+\log d)\exp(-k_{2}n/d^{5}), (18)

the following bounds hold simultaneously for 0≤u≤U∧τ0\leq u\leq U\wedge\tau, where z=1−e−uz=1-e^{-u}:

|Q⁡(u)−Dα​(u)|<k2​{n/d3,0≤z≤L/d3,n​d3​z2,L/d3<z≤η/d,n​d,η/d<z≤1/2.|Q(u)-D_{\alpha}(u)|<\frac{k}{2}\begin{cases}n/d^{3},&0\leq z\leq L/d^{3},\\ nd^{3}z^{2},&L/d^{3}<z\leq\eta/d,\\ nd,&\eta/d<z\leq 1/2.\end{cases}

For size a−a_{-}, on the same event, if u∗≤τu_{*}\leq\tau then |Q⁡(u∗)−Dα−​(u∗)|<k​n/(2​d3)|Q(u_{*})-D_{\alpha_{-}}(u_{*})|<kn/(2d^{3}).

The proof in Appendix A uses separate vertex, seed and stopped-queue estimates at the three drift scales.

For a−a_{-}, if τ≥u∗\tau\geq u_{*} the queue would be less than −1-1 at u∗u_{*}, contradicting (17). Thus τ<u∗\tau<u_{*}. For a+a_{+}, stopping at any τ≤U\tau\leq U would give Q⁡(τ)>0Q(\tau)>0, again a contradiction. Thus τ>U\tau>U.

Counts at the two outcomes.

In the subcritical case every eventually active nonseed vertex satisfies Xi​(u∗)≥RiX_{i}(u_{*})\geq R_{i}. The indicators of these events over all vertices are independent under the unconditioned clock and threshold law, and their sum has mean at most

μ∗≤∑i[π​di​z∗+(di2)​z∗2]≤C3​n/d3,z∗=b/K.\mu_{*}\leq\sum_{i}\left[\pi d_{i}z_{*}+\binom{d_{i}}{2}z_{*}^{2}\right]\leq C_{3}n/d^{3},\qquad z_{*}=b/K.

Bernstein’s inequality for Bernoulli sums, with deviation n/d3n/d^{3}, bounds the probability that this sum exceeds (C3+1)​n/d3(C_{3}+1)n/d^{3} by exp(−k3n/d3)\exp(-k_{3}n/d^{3}). Adding a−=O⁡(n/d4)a_{-}=O(n/d^{4}) proves the required count on the intersection with the stopping event. Independence of these two events is not required.

For the supercritical case put NU=∑i𝟏{Xi(U)<Ri}N_{U}=\sum_{i}\mathbf{1}_{\{X_{i}(U)<R_{i}\}}. These indicators are independent under the unconditioned clock and threshold law, with

μU=𝔼​NU=∑i2−di​[1+(1−π)​di]≤n⁡(1+Δ)​2−δ.\mu_{U}=\mathbb{E}N_{U}=\sum_{i}2^{-d_{i}}[1+(1-\pi)d_{i}]\leq n(1+\Delta)2^{-\delta}.

Hoeffding gives

Pr⁡(NU>μU+n2/3)≤e−2​n1/3.\Pr(N_{U}>\mu_{U}+n^{2/3})\leq e^{-2n^{1/3}}. (19)

Take k4=2k_{4}=2 in (20). On {τ>U}\{\tau>U\} every ultimately inactive vertex has Xi​(U)<RiX_{i}(U)<R_{i}, since no end of an inactive vertex was manually removed. Intersecting passage and this unconditional count event therefore gives

n−|A∞|≤NU≤μU+n2/3≤B+n[d2−d+C​d+n−1/3].n-|A_{\infty}|\leq N_{U}\leq\mu_{U}+n^{2/3}\leq B_{+}n[d2^{-d+C\sqrt{d}}+n^{-1/3}].

Simplicity, graphicality and uniformity.

For Mr=∑i(di)rM_{r}=\sum_{i}(d_{i})_{r} and ν=M2/M=d−1+vn\nu=M_{2}/M=d-1+v_{n}, Lemma 5.1 of McKay and Wormald (1991) gives, in the present regime,

logs=−ν/2−ν2/4+O(d3/n),s=Pr{the pairing is simple}≥e−C0​d2.\log s=-\nu/2-\nu^{2}/4+O(d^{3}/n),\qquad s=\Pr\{\text{the pairing is simple}\}\geq e^{-C_{0}d^{2}}.

Indeed its condition Δ=o⁡(M1/3)\Delta=o(M^{1/3}) follows from Δ3/M=O⁡(d2/n)=o⁡(1)\Delta^{3}/M=O(d^{2}/n)=o(1). Its additional terms are O⁡(Δ4/M)O(\Delta^{4}/M) and its remainder is O⁡(Δ3/M)O(\Delta^{3}/M), by Mr≤M​Δr−1M_{r}\leq M\Delta^{r-1}; this yields the displayed specialization. The positive probability also proves eventual graphicality. Every simple graph has exactly ∏idi!\prod_{i}d_{i}! pairings, so the conditional graph is uniform simple. The full pairing is independent of thresholds and seeds, whose joint law is therefore preserved. The clocks need not stay independent after conditioning.

Divide the sum of all applicable bad-event probabilities by ss. For either reference outcome a common upper envelope is

eC0​d2[C2(1+d2)(1+logd)e−k2n/d5+e−k3n/d3+4e−k4​n1/3]=o(1).e^{C_{0}d^{2}}\left[C_{2}(1+d^{2})(1+\log d)e^{-k_{2}n/d^{5}}+e^{-k_{3}n/d^{3}}+4e^{-k_{4}n^{1/3}}\right]=o(1). (20)

This uses only

n/d5d2=nd7→∞,n/d5log⁡n≥n2/7log⁡n→∞,d2n1/3→0,\frac{n/d^{5}}{d^{2}}=\frac{n}{d^{7}}\to\infty,\qquad\frac{n/d^{5}}{\log n}\geq\frac{n^{2/7}}{\log n}\to\infty,\qquad\frac{d^{2}}{n^{1/3}}\to 0,

where the middle inequality holds eventually. In particular it does not require d2≫log⁡nd^{2}\gg\log n. Every permitted subcritical size is at most a−a_{-}, and every permitted supercritical size is at least a+a_{+} eventually, since n​A→∞nA\to\infty. The independent permutation coupling in paragraph 2.1 transfers the reference conclusions by monotonicity. The empty and full seed cases are immediate. This completes the proof.

4 Proof for independent edges

We specialize the independent-mark construction and the distribution-free empirical-process argument of Janson et al. (2012) to the threshold mixture.

Put p=d/np=d/n and N=n−aN=n-a. All assertions below concern sufficiently large nn, so 0<p<1/20<p<1/2 and 0<π<10<\pi<1.

Condition on a particular seed set of size aa. At each real step ii, choose one active, unused vertex uiu_{i} by a deterministic rule based only on the revealed history and thresholds. Reveal its edges to all other unused vertices. These edges are fresh: neither endpoint was previously used. Conditional on the history and all thresholds, they are independent Bernoulli(p)(p) variables. For each nonseed vertex vv, set Iv​(i)I_{v}(i) equal to this edge indicator when vv is a target of the step; in every other cell (including v=uiv=u_{i}) insert a fresh independent Bernoulli(p)(p) variable. Thus each new column has product Bernoulli(p)(p) law independent of all preceding columns and thresholds. After real exploration stops, fill the remaining columns with fresh variables. Unexposed graph edges are completed independently. Deferred decisions therefore give exactly the required graph law, independent of the thresholds, and an iid mark array independent of the thresholds. The artificial cells are auxiliary variables, not additional graph edges.

For integer 0≤t≤n0\leq t\leq n, define

Mv(t)=∑i=1tIv(i),S(t)=∑v∉A0𝟏{Mv(t)≥Rv},L(t)=a+S(t)−t.M_{v}(t)=\sum_{i=1}^{t}I_{v}(i),\quad S(t)=\sum_{v\notin A_{0}}{\bf 1}_{\{M_{v}(t)\geq R_{v}\}},\quad L(t)=a+S(t)-t.

Before a nonseed vertex first becomes active it is unused, and all its marks are genuine edges from distinct used vertices. After activation its mark total stays above its threshold. Hence up to and including real stopping the active count is exactly a+S⁡(t)a+S(t). Since L⁡(t+1)−L⁡(t)≥−1L(t+1)-L(t)\geq-1, exploration stops at

T=min⁡{0≤t≤n:L⁡(t)≤0},L⁡(T)=0,|A∞|=T.T=\min\{0\leq t\leq n:L(t)\leq 0\},\qquad L(T)=0,\qquad|A_{\infty}|=T. (21)

The minimum exists because L⁡(n)≤0L(n)\leq 0. At stopping every active vertex has been used, and every inactive vertex has fewer than RvR_{v} neighbours in that active set. The set is closed, and every activation used in constructing it was a legal bootstrap activation, proving the last identity. When a=0a=0, T=0T=0 directly. No activation after TT in the auxiliary array is declared a real activation.

Independence of rows gives, at each deterministic integer time,

S⁡(t)∼Bin⁡(N,q⁡(t)),q⁡(t)=1−(1−p)t−(1−π)​t​p​(1−p)t−1​(t≥1),q⁡(0)=0.S(t)\sim\operatorname{Bin}(N,q(t)),\quad q(t)=1-(1-p)^{t}-(1-\pi)tp(1-p)^{t-1}\ (t\geq 1),\quad q(0)=0. (22)

Different times need not be independent. Write F=FEF=F_{\rm E} from Section 2.2, z=t/nz=t/n and hα=α+(1−α)​F−zh_{\alpha}=\alpha+(1-\alpha)F-z. Factorial moments give

q⁡(t)≤z+d2​z2/2,|q⁡(t)−F⁡(z)|≤d2​z/n.q(t)\leq z+d^{2}z^{2}/2,\qquad|q(t)-F(z)|\leq d^{2}z/n. (23)

For the second bound, couple Bernoulli(p)(p) and Poisson(p)(p) with mismatch probability p⁡(1−e−p)≤p2p(1-e^{-p})\leq p^{2}, take tt independent copies and the same independent threshold. For μa​(t)=a+N​q​(t)−t\mu_{a}(t)=a+Nq(t)-t this gives

|μa​(t)−n​hα​(t/n)|≤d2​z.|\mu_{a}(t)-nh_{\alpha}(t/n)|\leq d^{2}z. (24)
Lemma 9 (Maximal control of the mixed empirical process).

Let Y1,…,YNY_{1},\ldots,Y_{N} be independent identically distributed positive integer variables with CDF qq, where q⁡(0)=0q(0)=0, 0<q⁡(t)<10<q(t)<1 for finite t≥1t\geq 1, and q⁡(t)↑1q(t)\uparrow 1. Let N≤nN\leq n and Dt=∑v𝟏{Yv≤t}−Nq(t)D_{t}=\sum_{v}\mathbf{1}_{\{Y_{v}\leq t\}}-Nq(t). Then for x>0x>0 and each integer u≥0u\geq 0,

Pr⁡(supt≤u|Dt|>x)≤16​n​q​(u)/x2,Pr⁡(supt≥0|Dt|>x)≤8​n/x2.\Pr(\sup_{t\leq u}|D_{t}|>x)\leq 16nq(u)/x^{2},\qquad\Pr(\sup_{t\geq 0}|D_{t}|>x)\leq 8n/x^{2}. (25)
Proof.

Use the own indicator filtrations ℱt=σ(𝟏{Yv≤s}:s≤t,v)\mathcal{F}_{t}=\sigma(\mathbf{1}_{\{Y_{v}\leq s\}}:s\leq t,v) and 𝒢t=σ(𝟏{Yv≤s}:s≥t,v)\mathcal{G}_{t}=\sigma(\mathbf{1}_{\{Y_{v}\leq s\}}:s\geq t,v). The processes Dt/(1−q⁡(t))D_{t}/(1-q(t)) and Dt/q⁡(t)D_{t}/q(t) are respectively forward and reverse martingales where their denominators are nonzero. For an indicator not yet one, the next hazard is (q⁡(t+1)−q⁡(t))/(1−q⁡(t))(q(t+1)-q(t))/(1-q(t)); in reverse, conditional on an indicator being one at t+1t+1, its probability of being one at tt is q⁡(t)/q⁡(t+1)q(t)/q(t+1). These identities prove the conditional expectations; independence permits summation. No thresholds are revealed in these filtrations. Doob’s L2L^{2} inequality and Var⁡(Du)=N​q​(u)​(1−q⁡(u))\operatorname{Var}(D_{u})=Nq(u)(1-q(u)) give

𝔼​supt≤u|Dt|2≤4​N​q​(u)/(1−q⁡(u))≤8​n​q​(u)(q⁡(u)≤1/2),\mathbb{E}\sup_{t\leq u}|D_{t}|^{2}\leq 4Nq(u)/(1-q(u))\leq 8nq(u)\quad(q(u)\leq 1/2),

and 𝔼​supt≥u|Dt|2≤4​N​(1−q⁡(u))/q⁡(u)\mathbb{E}\sup_{t\geq u}|D_{t}|^{2}\leq 4N(1-q(u))/q(u) if q⁡(u)≥1/2q(u)\geq 1/2. For the reverse bound first use a finite reversed horizon, then let it tend to infinity. Let t1t_{1} be the last integer with q⁡(t1)≤1/2q(t_{1})\leq 1/2. The left bound at t1t_{1} and the right bound at t1+1t_{1}+1 are each at most 4​N4N, even when qq jumps across 1/21/2. Thus the global second moment is at most 8​n8n. If q⁡(u)>1/2q(u)>1/2, this is also at most 16​n​q​(u)16nq(u). Markov’s inequality proves both assertions; u=0u=0 is deterministic. This is the empirical-process proof of Lemmas 7.2–7.3 of Janson et al. (2012), applied to the mixed CDF. ∎

Apply this lemma to Yv=min⁡{t:Mv​(t)≥Rv}Y_{v}=\min\{t:M_{v}(t)\geq R_{v}\}. Extend the iid auxiliary coins independently beyond nn if necessary; these extra coins are not graph edges. The YvY_{v} are iid with the mixed CDF in (22), including its continuation. Take reference sizes

a−=⌊(1−γ/2)​n​AE⌋,a+=⌈(1+γ/2)​n​AE⌉.a_{-}=\lfloor(1-\gamma/2)nA_{\rm E}\rfloor,\qquad a_{+}=\lceil(1+\gamma/2)nA_{\rm E}\rceil.

Choose LL as in Lemma 7. Since Aquad/AE=1+O⁡(d−1)A^{\rm quad}/A_{\rm E}=1+O(d^{-1}) and 1/n=o⁡(d−4)1/n=o(d^{-4}), Lemma 7 applies with margin γ/2\gamma/2 and o⁡(Aquad)o(A^{\rm quad}) perturbations. Set η=ε\eta=\varepsilon, m=⌊n/2⌋m=\lfloor n/2\rfloor and t∗=round⁡(n​b/K)t_{*}=\operatorname{round}(nb/K). The three errors in (24), relative to the corresponding queue scales, are bounded by L​d3/nLd^{3}/n, d3/(L​n)d^{3}/(Ln) and d2/(2​n)d^{2}/(2n), all o⁡(1)o(1). Also t∗=O⁡(n/d3)t_{*}=O(n/d^{3}) is early; F′=O⁡(1)F^{\prime}=O(1) there makes time rounding an O⁡(1)=o⁡(n/d4)O(1)=o(n/d^{4}) drift error. Consequently, for some fixed k>0k>0,

μa+(t)≥2k{n/d4,z≤L/d3,n​d2​z2,L/d3<z≤η/d,n,η/d<z≤1/2,μa−(t∗)≤−2kn/d4.\mu_{a_{+}}(t)\geq 2k\begin{cases}n/d^{4},&z\leq L/d^{3},\\ nd^{2}z^{2},&L/d^{3}<z\leq\eta/d,\\ n,&\eta/d<z\leq 1/2,\end{cases}\qquad\mu_{a_{-}}(t_{*})\leq-2kn/d^{4}. (26)

The early horizon u=⌊n​L/d3⌋u=\lfloor nL/d^{3}\rfloor has q⁡(u)=O⁡(d−3)q(u)=O(d^{-3}). With budget k​n/d4kn/d^{4}, (25) gives failure O⁡(d5/n)O(d^{5}/n), also controlling the negative test. For middle intervals put sj=2j​L/d3<η/ds_{j}=2^{j}L/d^{3}<\eta/d and uj=⌊n​min⁡(2​sj,η/d)⌋u_{j}=\lfloor n\min(2s_{j},\eta/d)\rfloor. For sj≤t/n≤min⁡(2​sj,η/d)s_{j}\leq t/n\leq\min(2s_{j},\eta/d) use budget k​n​d2​sj2knd^{2}s_{j}^{2}. Since q⁡(uj)≤C⁡(sj+d2​sj2)q(u_{j})\leq C(s_{j}+d^{2}s_{j}^{2}), failure is at most

C⁡{(n​d4​sj3)−1+(n​d2​sj2)−1}.C\{(nd^{4}s_{j}^{3})^{-1}+(nd^{2}s_{j}^{2})^{-1}\}.

The sums of 2−3​j2^{-3j} and 2−2​j2^{-2j} are bounded, giving O⁡((d5+d4)/n)O((d^{5}+d^{4})/n). These intervals and the early horizon cover all integer times up to η/d\eta/d; empty intervals may be skipped. The late global bound with budget k​nkn costs O⁡(1/n)O(1/n). No independence of intervals or survival conditioning is used. Hence

Pr{∃t≤m:L+(t)≤0}≤Cd5/n=o(1),Pr{L−(t∗)≥0}≤Cd5/n.\Pr\{\exists t\leq m:L_{+}(t)\leq 0\}\leq Cd^{5}/n=o(1),\qquad\Pr\{L_{-}(t_{*})\geq 0\}\leq Cd^{5}/n. (27)

By (21), the negative auxiliary test forces T≤t∗T\leq t_{*}, giving |A∞|=O⁡(n/d3)|A_{\infty}|=O(n/d^{3}) below the threshold. Above it, T>mT>m, so the count at mm is a real active count. Separately, unconditional binomial Hoeffding gives Pr⁡(|S⁡(m)−N​q​(m)|>n2/3)≤2​e−2​n1/3\Pr(|S(m)-Nq(m)|>n^{2/3})\leq 2e^{-2n^{1/3}}. Intersect this event with passage, without conditioning the binomial law on survival. Since p≤1/2p\leq 1/2, m​p≤d/2mp\leq d/2 and m​p≥d/2−d/nmp\geq d/2-d/n,

1−q(m)=(1−p)m[1+(1−π)mp/(1−p)]≤(1+d)e−d/2+d/n.1-q(m)=(1-p)^{m}[1+(1-\pi)mp/(1-p)]\leq(1+d)e^{-d/2+d/n}.

Thus

n−|A∞|≤n−a−S(m)≤n(1+d)e−d/2+d/n+n2/3,n-|A_{\infty}|\leq n-a-S(m)\leq n(1+d)e^{-d/2+d/n}+n^{2/3},

with failure at most C​d5/n+2​e−2​n1/3Cd^{5}/n+2e^{-2n^{1/3}}. This residual is o⁡(n)o(n) for every permitted d→∞d\to\infty. Since n​AE→∞nA_{\rm E}\to\infty, each allowed subcritical size is at most a−a_{-} and each allowed supercritical size is at least a+a_{+} eventually. Paragraph 2.1 transfers the conclusions. The estimates conditional on a seed set fixed in advance are uniform in its labels. They do not permit adaptive seed selection or assert a simultaneous guarantee over all sets. The cases a=0,na=0,n are immediate. This proves Theorem 2.

5 Precision required of a static sandwich

For common thresholds and seeds, graph inclusion preserves active sets, by induction on activation rounds. To examine the precision needed for coefficient transfer, we first record a consequence of the fixed-parameter theorem.

Lemma 10 (A compact range of effective parameters).

Suppose r→∞r\to\infty and r5/n→0r^{5}/n\to 0, and fix 0<m0≤M0<∞0<m_{0}\leq M_{0}<\infty and γ∈(0,1)\gamma\in(0,1). Let cn′∈[m0,M0]c_{n}^{\prime}\in[m_{0},M_{0}] be deterministic and take G⁡(n,r/n)G(n,r/n) with independent thresholds satisfying Pr⁡(Ri=1)=(1−cn′/r)/r\Pr(R_{i}=1)=(1-c_{n}^{\prime}/r)/r and independent uniform seeds of prescribed size aa. Put Tn′=n​(cn′)2/(2​r4)T_{n}^{\prime}=n(c_{n}^{\prime})^{2}/(2r^{4}). Then

a≤(1−γ)​Tn′⟹|A∞|=O⁡(n/r3)with high probability,a≥(1+γ)​Tn′⟹n−|A∞|=O⁡(ℛE​(n,r))with high probability.\begin{split}a\leq(1-\gamma)T_{n}^{\prime}&\ \Longrightarrow\quad|A_{\infty}|=O(n/r^{3})\quad\hbox{with high probability},\\ a\geq(1+\gamma)T_{n}^{\prime}&\ \Longrightarrow\quad n-|A_{\infty}|=O(\mathcal{R}_{\rm E}(n,r))\quad\hbox{with high probability}.\end{split}

The constants may depend on m0,M0,γm_{0},M_{0},\gamma only. The E conclusion of Corollary 5 also holds with rr in place of dd.

Proof.

Cover [m0,M0][m_{0},M_{0}] by finitely many intervals [uj,vj]⊂(0,∞)[u_{j},v_{j}]\subset(0,\infty) so short that

(1−γ)​vj2≤(1−γ/2)​uj2,(1+γ)​uj2≥(1+γ/2)​vj2.(1-\gamma)v_{j}^{2}\leq(1-\gamma/2)u_{j}^{2},\qquad(1+\gamma)u_{j}^{2}\geq(1+\gamma/2)v_{j}^{2}.

Such a cover exists because both required upper bounds on vj/ujv_{j}/u_{j} are strictly larger than one. At fixed rr, increasing the parameter cc decreases the probability of threshold one. Couple thresholds using common independent uniform labels. For fixed graph and seeds, the final active set is then decreasing in cc. If cn′∈[uj,vj]c_{n}^{\prime}\in[u_{j},v_{j}], the subcritical comparison is with the easier model c=ujc=u_{j}, and the supercritical comparison with the harder model c=vjc=v_{j}. The displayed inequalities supply margin γ/2\gamma/2. Apply Theorem 2 to the finitely many fixed endpoints and take the maximum of their constants and a union bound over their errors. If an interval is selected only on a subsequence, extend its tested seed sizes outside that subsequence by zero for the subcritical application and by nn for the supercritical application. The fixed-parameter theorem then applies on a full sequence. Finally apply the explicit residual bound to obtain the logarithmic assertion. ∎

Fix c>0c>0 and let dd satisfy (8). For each nn, keep the threshold probability π=(1−c/d)/d\pi=(1-c/d)/d unchanged while replacing the edge-probability parameter dd by r=(1+δn)​d>0r=(1+\delta_{n})d>0. Write β=c/d\beta=c/d. Assume, for some fixed 0<m≤M<∞0<m\leq M<\infty,

md≤bn′:=1−π​r=β−δn​(1−β)≤Md.\frac{m}{d}\leq b_{n}^{\prime}:=1-\pi r=\beta-\delta_{n}(1-\beta)\leq\frac{M}{d}. (28)

Then δn=O⁡(1/d)\delta_{n}=O(1/d), r/d→1r/d\to 1, and cn′=r​bn′c_{n}^{\prime}=rb_{n}^{\prime} stays in a fixed compact subinterval of (0,∞)(0,\infty). Moreover π=(1−cn′/r)/r\pi=(1-c_{n}^{\prime}/r)/r. Lemma 10 therefore gives the leading seed scale Tn′=n​(bn′)2/(2​r2)T_{n}^{\prime}=n(b_{n}^{\prime})^{2}/(2r^{2}), with both fixed-margin outcomes and their stated residual bounds. Relative to the baseline scale, the exact ratio of these leading expressions is

Tn′n​c2/(2​d4)=[1−δn​(1−β)/β]2(1+δn)2=(1−δnβ⁡(1+δn))2.\frac{T_{n}^{\prime}}{nc^{2}/(2d^{4})}=\frac{[1-\delta_{n}(1-\beta)/\beta]^{2}}{(1+\delta_{n})^{2}}=\left(1-\frac{\delta_{n}}{\beta(1+\delta_{n})}\right)^{2}. (29)

The expression before squaring is positive under (28). Consequently this ratio tends to one if and only if δn=o⁡(β)=o⁡(1/d)\delta_{n}=o(\beta)=o(1/d). For example, δn=t/d\delta_{n}=t/d with fixed t<ct<c gives the limiting ratio (c−t)2/c2(c-t)^{2}/c^{2}. A nonpositive or vanishing normalized deficit is outside (28); squaring does not extend the theorem there. Suppose every displacement in the band |δ|≤εn|\delta|\leq\varepsilon_{n} satisfies (28) with the same fixed constants m,Mm,M. The leading coefficient is then preserved to relative error o⁡(1)o(1) uniformly over the band if and only if εn=o⁡(1/d)\varepsilon_{n}=o(1/d). Necessity follows already from the endpoint δ=−εn\delta=-\varepsilon_{n}, and sufficiency follows from (29). This is a statement about a full band, not about a possibly much smaller actual displacement within an upper bound.

Proposition 11 (Static inclusion at coefficient precision).

Let d=dnd=d_{n} be integer with n​dnd even, d→∞d\to\infty and d=o⁡(n1/7)d=o(n^{1/7}), and let 0≤εn=o⁡(1/d)0\leq\varepsilon_{n}=o(1/d). For every coupling on the same labelled vertex set of

G−∼G⁡(n,(1−εn)​d/n),GR∼Gn,d,G^{-}\sim G(n,(1-\varepsilon_{n})d/n),\qquad G_{\rm R}\sim G_{n,d},

where Gn,dG_{n,d} is the uniform simple dd-regular graph,

Pr⁡(G−⊆GR)≤12+o⁡(1).\Pr(G^{-}\subseteq G_{\rm R})\leq\tfrac{1}{2}+o(1).

The error term can be chosen independently of the coupling. In particular, inclusion cannot hold with probability tending to one.

Proof.

At any fixed vertex let YY be its degree in G−G^{-}. Set p=(1−εn)​d/np=(1-\varepsilon_{n})d/n and N=n−1N=n-1. Then

Y∼Bin⁡(N,p),μ=N​p=(1−εn)​d​(1−1/n),σ2=N​p​(1−p)∼d⟶∞,Y\sim\operatorname{Bin}(N,p),\quad\mu=Np=(1-\varepsilon_{n})d(1-1/n),\quad\sigma^{2}=Np(1-p)\sim d\longrightarrow\infty,
d−μ=εn​d+(1−εn)​d/n=o⁡(1).d-\mu=\varepsilon_{n}d+(1-\varepsilon_{n})d/n=o(1).

For completeness, write Y−μ=∑j=1NZjY-\mu=\sum_{j=1}^{N}Z_{j} with independent centred Bernoulli summands. For fixed real tt,

𝔼​ei​t​Zj/σ=1−t2​𝔼​Zj22​σ2+ρj,∑j|ρj|≤|t|36​σ3​∑j𝔼​|Zj|3≤|t|36​σ⟶0.\mathbb{E}e^{itZ_{j}/\sigma}=1-\frac{t^{2}\mathbb{E}Z_{j}^{2}}{2\sigma^{2}}+\rho_{j},\qquad\sum_{j}|\rho_{j}|\leq\frac{|t|^{3}}{6\sigma^{3}}\sum_{j}\mathbb{E}|Z_{j}|^{3}\leq\frac{|t|^{3}}{6\sigma}\longrightarrow 0.

The maximum modulus of the terms added to one tends to zero, and the sum of their moduli is bounded. Taking logarithms of their product therefore yields −t2/2+o(1)-t^{2}/2+o(1). Thus (Y−μ)/σ(Y-\mu)/\sigma converges in law to a standard normal variable. Since (d−μ)/σ→0(d-\mu)/\sigma\to 0, Pr⁡(Y≤d)→1/2\Pr(Y\leq d)\to 1/2. Inclusion in a dd-regular graph requires Y≤dY\leq d, whatever the coupling. Its probability is therefore bounded by this same marginal probability, proving the assertion. ∎

Together with (29), this obstructs direct transfer of the leading coefficient by a static two-sided inclusion sandwich of relative width o⁡(1/d)o(1/d) in the common degree range. It does not rule out coarser sandwiches or other comparison arguments.

6 Deterministic finite-degree corrections

We now refine the quadratic approximation A=b2/(2​K)A=b^{2}/(2K) using the deterministic response functions. The assumptions are stated locally: these calculations do not require the degree ranges used in the probability theorems.

αdet=max0≤z≤1/2⁡R⁡(z),R⁡(z)=z−F⁡(z)1−F⁡(z).\alpha_{\rm det}=\max_{0\leq z\leq 1/2}R(z),\qquad R(z)=\frac{z-F(z)}{1-F(z)}. (30)

Indeed hα​(z)=(1−F⁡(z))​(α−R⁡(z))h_{\alpha}(z)=(1-F(z))(\alpha-R(z)), and 1−F⁡(z)>01-F(z)>0 on this interval. This barrier refines the deterministic quadratic approximation; it is not an identification of the finite-nn random critical-window centre.

6.1 Exact regular barrier

For regular degrees, let d≥4d\geq 4 and 0≤π<1/(d−1)0\leq\pi<1/(d-1), and put b=1−π⁡(d−1)∈(0,1]b=1-\pi(d-1)\in(0,1]. The deterministic barrier is explicit:

z^reg=b(d−2)​(d−3+b),αdetreg=1−(1+b/(d−3))d−3(1+b/(d−2))d−2.\widehat{z}_{\rm reg}=\frac{b}{(d-2)(d-3+b)},\qquad\alpha_{\rm det}^{\rm reg}=1-\frac{(1+b/(d-3))^{d-3}}{(1+b/(d-2))^{d-2}}.

Indeed Rd=1−Jd−1R_{d}=1-J_{d}^{-1}, where Jd=(1−z)d−3​[1+(d−3+b)​z]J_{d}=(1-z)^{d-3}[1+(d-3+b)z], and Jd′=(1−z)d−4​[b−(d−2)​(d−3+b)​z]J_{d}^{\prime}=(1-z)^{d-4}[b-(d-2)(d-3+b)z]. The optimiser satisfies 0<z^reg≤1/(d−2)2≤1/40<\widehat{z}_{\rm reg}\leq 1/(d-2)^{2}\leq 1/4, so it belongs to the interval in (30). At π=0\pi=0 this reduces to the threshold-two response formula of Balogh and Pittel (2007); here it is used only as a deterministic identity. For the choice π=(1−c/d)/d\pi=(1-c/d)/d, put m=d−3m=d-3. The logarithm of Jd​(z^reg)J_{d}(\widehat{z}_{\rm reg}) is

ℓ=(m+1)​log⁡(1+b/(m+1))−m​log⁡(1+b/m)=b22​m​(m+1)+O⁡(d−6).\ell=(m+1)\log(1+b/(m+1))-m\log(1+b/m)=\frac{b^{2}}{2m(m+1)}+O(d^{-6}).

The linear terms cancel; the cubic difference is b33​[(m+1)−2−m−2]=O⁡(d−6)\frac{b^{3}}{3}[(m+1)^{-2}-m^{-2}]=O(d^{-6}), and each fourth-order remainder is O⁡(d−7)O(d^{-7}). Since αdetreg=1−e−ℓ=ℓ+O⁡(d−8)\alpha_{\rm det}^{\rm reg}=1-e^{-\ell}=\ell+O(d^{-8}), b=(c+1)/d−c/d2b=(c+1)/d-c/d^{2} and [m⁡(m+1)]−1=d−2​(1+5/d+O⁡(d−2))[m(m+1)]^{-1}=d^{-2}(1+5/d+O(d^{-2})) give

αdetreg=(c+1)22​d4+(c+1)​(3​c+5)2​d5+O⁡(d−6).\alpha_{\rm det}^{\rm reg}=\frac{(c+1)^{2}}{2d^{4}}+\frac{(c+1)(3c+5)}{2d^{5}}+O(d^{-6}).

6.2 General degree sequence

Proposition 12 (Finite-degree expansion).

Fix c>0c>0, C≥0C\geq 0 and κ>0\kappa>0. Let DD have the empirical law of nonnegative integers d1,…,dnd_{1},\ldots,d_{n}, with exact mean d→∞d\to\infty, and assume

maxi⁡|di−d|≤C​d,vn=Var⁡(D)/d,ρ=c+1−vn≥κ.\max_{i}|d_{i}-d|\leq C\sqrt{d},\qquad v_{n}=\operatorname{Var}(D)/d,\qquad\rho=c+1-v_{n}\geq\kappa.

Set π=d−1−c​d−2\pi=d^{-1}-cd^{-2} and (x)j=x(x−1)⋯(x−j+1)(x)_{j}=x(x-1)\cdots(x-j+1). For sufficiently large dd define

B⁡(z)=1d𝔼[D{(1−z)D−1+(1−π)(D−1)z(1−z)D−2}],F=1−B,R⁡(z)=z−F⁡(z)1−F⁡(z),αdet=max0≤z≤1/2R(z),b=1−π𝔼⁡[(D)2]d,K=(1−2π)𝔼⁡[(D)3]d,A=b22​K,L3=−(2−3π)𝔼⁡[(D)4]d,L4=(3−4π)𝔼⁡[(D)5]d.\begin{split}B(z)&=\frac{1}{d}\mathbb{E}\!\left[D\left\{(1-z)^{D-1}+(1-\pi)(D-1)z(1-z)^{D-2}\right\}\right],\qquad F=1-B,\\ R(z)&=\frac{z-F(z)}{1-F(z)},\qquad\alpha_{\rm det}=\max_{0\leq z\leq 1/2}R(z),\\ b&=1-\pi\frac{\mathbb{E}[(D)_{2}]}{d},\qquad K=(1-2\pi)\frac{\mathbb{E}[(D)_{3}]}{d},\qquad A=\frac{b^{2}}{2K},\\ L_{3}&=-(2-3\pi)\frac{\mathbb{E}[(D)_{4}]}{d},\qquad L_{4}=(3-4\pi)\frac{\mathbb{E}[(D)_{5}]}{d}.\end{split}

The maximum is attained uniquely, at

z^=bK−L3​b22​K3+b22​K2+O⁡(d−7),\widehat{z}=\frac{b}{K}-\frac{L_{3}b^{2}}{2K^{3}}+\frac{b^{2}}{2K^{2}}+O(d^{-7}), (31)

and

αdet=A−L3​b36​K3+A​bK−A2+L32​b48​K5−L4​b424​K4+O⁡(d−9).\begin{split}\alpha_{\rm det}={}&A-\frac{L_{3}b^{3}}{6K^{3}}+\frac{Ab}{K}-A^{2}\\ &+\frac{L_{3}^{2}b^{4}}{8K^{5}}-\frac{L_{4}b^{4}}{24K^{4}}+O(d^{-9}).\end{split} (32)

All coefficients here are exact empirical moments. The remainders are uniform for fixed c,C,κc,C,\kappa; no limit of vnv_{n} and no relation between nn and dd are required. This is a deterministic response statement, not a graphicality assertion or a random critical-window theorem.

Proof.

The deterministic P response verification in Section 2.2 uses exactly the assumptions of this proposition. It gives F′​(0)=1−bF^{\prime}(0)=1-b, F′′​(0)=KF^{\prime\prime}(0)=K, F′′′​(0)=L3F^{\prime\prime\prime}(0)=L_{3}, F′′′′​(0)=L4F^{\prime\prime\prime\prime}(0)=L_{4} and |F(j)|=O⁡(dj)|F^{(j)}|=O(d^{j}) for 2≤j≤52\leq j\leq 5 on the early interval. Lemma 7 gives the unique global maximiser in (0,8​b/K)(0,8b/K), with b≍d−1b\asymp d^{-1}, K≍d2K\asymp d^{2} and A≍d−4A\asymp d^{-4}. No probability degree range is used.

Put z0=b/Kz_{0}=b/K and N=z−FN=z-F. On [0,8​b/K][0,8b/K],

N⁡(z)=b​z−K​z2/2−L3​z3/6−L4​z4/24+O⁡(d5​z5),R′′​(z)=−K⁡(1+O⁡(d−2)).N(z)=bz-Kz^{2}/2-L_{3}z^{3}/6-L_{4}z^{4}/24+O(d^{5}z^{5}),\qquad R^{\prime\prime}(z)=-K(1+O(d^{-2})).

Here z0=O⁡(d−3)z_{0}=O(d^{-3}), L3=O⁡(d3)L_{3}=O(d^{3}) and L4=O⁡(d4)L_{4}=O(d^{4}). At z0z_{0} the numerator of R′R^{\prime} is

N′(z0)B(z0)+N(z0)F′(z0)=−L3z02/2+A+O(d−5).N^{\prime}(z_{0})B(z_{0})+N(z_{0})F^{\prime}(z_{0})=-L_{3}z_{0}^{2}/2+A+O(d^{-5}).

The mean value theorem first gives z^−z0=O⁡(d−5)\widehat{z}-z_{0}=O(d^{-5}); the same identity and curvature then give (31). Writing δ3=−L3z02/(2K)\delta_{3}=-L_{3}z_{0}^{2}/(2K), we have z^−z0=δ3+O⁡(d−6)\widehat{z}-z_{0}=\delta_{3}+O(d^{-6}). Completing the square yields

N⁡(z^)=A−L3​z03/6−L4​z04/24+L32​z04/(8​K)+O⁡(d−10).N(\widehat{z})=A-L_{3}z_{0}^{3}/6-L_{4}z_{0}^{4}/24+L_{3}^{2}z_{0}^{4}/(8K)+O(d^{-10}).

Indeed the neglected terms are bounded by constant multiples of d5​z05d^{5}z_{0}^{5}, K​d−12Kd^{-12}, |L3|​z0​δ32|L_{3}|z_{0}\delta_{3}^{2} and |L4|​z03​|δ3||L_{4}|z_{0}^{3}|\delta_{3}|, each O⁡(d−10)O(d^{-10}). Finally F⁡(z^)=z0−A+O⁡(d−5)F(\widehat{z})=z_{0}-A+O(d^{-5}), whence

R⁡(z^)=N⁡(z^)​(1+F⁡(z^)+O⁡(F​(z^)2))=N⁡(z^)+A​z0−A2+O⁡(d−9).R(\widehat{z})=N(\widehat{z})(1+F(\widehat{z})+O(F(\widehat{z})^{2}))=N(\widehat{z})+Az_{0}-A^{2}+O(d^{-9}).

The denominator thus leaves an O⁡(d−9)O(d^{-9}) remainder, although the numerator remainder above is O⁡(d−10)O(d^{-10}). This proves the claim. ∎

The expansion separates three levels of degree information. The leading term depends on vnv_{n} through the excess-degree deficit. The third central moment can first contribute at absolute order d−11/2d^{-11/2}. After matching the first three moments, a fourth-moment difference of order d2d^{2} can still change the deterministic barrier at order d−8d^{-8}. We now give the coefficients and an explicit example.

6.3 Variance, skewness, and two degree values

Let μj=𝔼⁡[(D−d)j]\mu_{j}=\mathbb{E}[(D-d)^{j}], ρ=c+1−vn\rho=c+1-v_{n}, r=c⁡(vn−1)r=c(v_{n}-1), k1=3​vn−5k_{1}=3v_{n}-5 and k2=8−9​vn+2​ck_{2}=8-9v_{n}+2c. The exact identities

b=ρ/d+r/d2,K=(1−2d+2​cd2)​[d2+(3​vn−3)​d+2−3​vn+μ3d]b=\rho/d+r/d^{2},\qquad K=\left(1-\frac{2}{d}+\frac{2c}{d^{2}}\right)\left[d^{2}+(3v_{n}-3)d+2-3v_{n}+\frac{\mu_{3}}{d}\right]

and μ3=O⁡(d3/2)\mu_{3}=O(d^{3/2}) give, by expanding (32),

αdet=ρ22​d4[1+2​r/ρ−k1d−μ3d3+r2/ρ2+k12−k2−2​r​k1/ρ+2​ρ/3d2+O(d−5/2)].\begin{split}\alpha_{\rm det}=\frac{\rho^{2}}{2d^{4}}\bigg[1&+\frac{2r/\rho-k_{1}}{d}-\frac{\mu_{3}}{d^{3}}\\ &+\frac{r^{2}/\rho^{2}+k_{1}^{2}-k_{2}-2rk_{1}/\rho+2\rho/3}{d^{2}}+O(d^{-5/2})\bigg].\end{split} (33)

The term 2​ρ/32\rho/3 comes from the cubic response; the denominator correction A​b/KAb/K has absolute order d−7d^{-7} and does not enter the displayed relative d−2d^{-2} coefficient. If μ3=0\mu_{3}=0, the remainder inside brackets improves to O⁡(d−3)O(d^{-3}). For equal empirical masses at d−sd-s and d+sd+s, require even nn and nonnegative integer values d−s,d+sd-s,d+s; then vn=s2/dv_{n}=s^{2}/d and μ3=0\mu_{3}=0 exactly. Graph applications also require even total degree n​dnd and the assumptions of the prescribed-degree probability theorem. The absolute remainder in (33) is O(d−13/2)O(d^{-13/2}), or O⁡(d−7)O(d^{-7}) when μ3=0\mu_{3}=0; it is not the O⁡(d−9)O(d^{-9}) remainder of the exact-coefficient formula. These expansions use actual empirical moments, with c+1−vn≥κ>0c+1-v_{n}\geq\kappa>0. A variance limit is optional and cannot replace vnv_{n} in the correction terms without a rate. For example, for integer dd and fixed 0≤v<c+10\leq v<c+1, s=⌊v​d⌋s=\lfloor\sqrt{vd}\rfloor gives vn=v+O(d−1/2)v_{n}=v+O(d^{-1/2}); this error can exceed the first relative d−1d^{-1} correction.

6.4 A distinction beyond variance

The third central moment can affect the barrier at order d−11/2d^{-11/2} through KK, as (33) shows. Even matching that moment leaves a further distinction. Indeed, expansion of the fourth factorial moment gives

𝔼⁡[(D)4]d=d3+(6​vn−6)​d2+(11−18​vn)​d+(11​vn−6)+(4−6/d)​μ3+μ4d.\frac{\mathbb{E}[(D)_{4}]}{d}=d^{3}+(6v_{n}-6)d^{2}+(11-18v_{n})d+(11v_{n}-6)+(4-6/d)\mu_{3}+\frac{\mu_{4}}{d}.

For two degree laws with the same d,vn,μ3d,v_{n},\mu_{3} and a common deviation bound, b,Kb,K agree exactly. Their L3L_{3} difference is −(2−3π)(μ4,2−μ4,1)/d=O(d)-(2-3\pi)(\mu_{4,2}-\mu_{4,1})/d=O(d), whereas their L4L_{4} difference is O⁡(d2)O(d^{2}): this follows by expanding (D)5(D)_{5} and using μ4=O⁡(d2)\mu_{4}=O(d^{2}), μ5=O⁡(d5/2)\mu_{5}=O(d^{5/2}). Consequently the differences of the L32L_{3}^{2} and L4L_{4} terms in (32) are O⁡(d−10)O(d^{-10}), and

αdet,2−αdet,1=(2−3​π)​b36​d​K3​(μ4,2−μ4,1)+O⁡(d−9).\alpha_{{\rm det},2}-\alpha_{{\rm det},1}=\frac{(2-3\pi)b^{3}}{6dK^{3}}(\mu_{4,2}-\mu_{4,1})+O(d^{-9}). (34)

For a concrete example take an integer s→∞s\to\infty and put d=s2d=s^{2}. The law with mass 1/21/2 at each of d−s,d+sd-s,d+s, and the law with mass 3/43/4 at dd and 1/81/8 at each of d−2​s,d+2​sd-2s,d+2s, both have vn=1v_{n}=1 and μ3=0\mu_{3}=0. Their fourth central moments differ by 3​d23d^{2}, so

αdet,2−αdet,1=c3​d−8+O⁡(d−9).\alpha_{{\rm det},2}-\alpha_{{\rm det},1}=c^{3}d^{-8}+O(d^{-9}).

Both are empirical degree laws when nn is divisible by eight, and admissible sequences can be chosen in (3). This distinguishes deterministic barriers at equal mean and variance; it does not resolve random threshold differences at this scale.

6.5 Independent-edge response

Fix c>0c>0 and set π=d−1−c​d−2\pi=d^{-1}-cd^{-2}. The Poisson response and its deterministic barrier are

Q⁡(x)=1−e−x​[1+(1−π)​x],P⁡(z)=z−Q⁡(d​z)1−Q⁡(d​z),αE,Pois=max0≤z≤1/2⁡P⁡(z).Q(x)=1-e^{-x}[1+(1-\pi)x],\qquad P(z)=\frac{z-Q(dz)}{1-Q(dz)},\qquad\alpha_{{\rm E},{\rm Pois}}=\max_{0\leq z\leq 1/2}P(z).

For d→∞d\to\infty, the Taylor calculation in Proposition 12, applied directly to FE​(z)=Q​(d​z)F_{\rm E}(z)=Q(dz), uses the exact coefficients

bE=c/d,KE=(1−2​π)​d2,L3,E=−(2−3​π)​d3,L4,E=(3−4​π)​d4.b_{\rm E}=c/d,\quad K_{\rm E}=(1-2\pi)d^{2},\quad L_{3,\rm E}=-(2-3\pi)d^{3},\quad L_{4,\rm E}=(3-4\pi)d^{4}.

It gives (32) with these coefficients and AEquad=bE2/(2​KE)A_{\rm E}^{\rm quad}=b_{\rm E}^{2}/(2K_{\rm E}), and in particular

αE,Pois=c22​d4​[1+2d+4−4​c/3d2]+O⁡(d−7).\alpha_{{\rm E},{\rm Pois}}=\frac{c^{2}}{2d^{4}}\left[1+\frac{2}{d}+\frac{4-4c/3}{d^{2}}\right]+O(d^{-7}). (35)

The derivative and localization bounds needed for this calculation are verified in the proof below; no bounded-support degree assumption is imposed on the Poisson response.

Proposition 13 (Integer-time binomial barrier).

Let nn be an integer, d→∞d\to\infty and n/d3→∞n/d^{3}\to\infty. Put p=d/np=d/n and, for integers 0≤t≤⌊n/2⌋0\leq t\leq\lfloor n/2\rfloor, define

q⁡(t)=1−(1−p)t​[1+(1−π)​t​p1−p],βn=max0≤t≤⌊n/2⌋⁡t/n−q⁡(t)1−q⁡(t).q(t)=1-(1-p)^{t}\left[1+\frac{(1-\pi)tp}{1-p}\right],\qquad\beta_{n}=\max_{0\leq t\leq\lfloor n/2\rfloor}\frac{t/n-q(t)}{1-q(t)}.

The maximum is over integers, and q⁡(0)=0q(0)=0. Then

|βn−αE,Pois|=O⁡(1n​d+d2n2),|\beta_{n}-\alpha_{{\rm E},{\rm Pois}}|=O\left(\frac{1}{nd}+\frac{d^{2}}{n^{2}}\right), (36)

and

βn=c22​d4​[1+2d+4−4​c/3d2]+O⁡(d−7+1n​d+d2n2).\beta_{n}=\frac{c^{2}}{2d^{4}}\left[1+\frac{2}{d}+\frac{4-4c/3}{d^{2}}\right]+O\left(d^{-7}+\frac{1}{nd}+\frac{d^{2}}{n^{2}}\right). (37)

The constants in (36) and (37) depend only on cc. Under d5/n→0d^{5}/n\to 0 the last remainder is o⁡(d−6)o(d^{-6}). An O⁡(d−7)O(d^{-7}) remainder is obtained if additionally d6=O⁡(n)d^{6}=O(n). The full exact-coefficient expression (32), with the Poisson coefficients above, transfers to βn\beta_{n} with remainder O⁡(d−9)O(d^{-9}) if d8=O⁡(n)d^{8}=O(n). Constants in these simplified remainders may also depend on the bounds for d6/nd^{6}/n or d8/nd^{8}/n, respectively.

Proof.

All assertions are for sufficiently large dd, so 0<π<10<\pi<1 and p<1/2p<1/2. For x=t​px=tp, r=t⁡[−log⁡(1−p)−p]r=t[-\log(1-p)-p] and Ax=1+(1−π)​xA_{x}=1+(1-\pi)x,

1−q⁡(t)=e−x−r​[Ax+(1−π)​x​p1−p],0≤r≤x​p2​(1−p).1-q(t)=e^{-x-r}\left[A_{x}+\frac{(1-\pi)xp}{1-p}\right],\qquad 0\leq r\leq\frac{xp}{2(1-p)}.

Using 1−e−r≤r1-e^{-r}\leq r and boundedness of e−x​(1+x)e^{-x}(1+x) on x≥0x\geq 0 gives, with z=t/nz=t/n,

|q⁡(t)−Q⁡(x)|≤e−x​[Ax​r+(1−π)​x​p1−p]≤C1​x​p=C1​d2​z/n.|q(t)-Q(x)|\leq e^{-x}\left[A_{x}r+\frac{(1-\pi)xp}{1-p}\right]\leq C_{1}xp=C_{1}d^{2}z/n. (38)

By the response verification and Lemma 7, the Poisson barrier has a unique maximiser zP∈(0,8​bE/KE)z_{P}\in(0,8b_{\rm E}/K_{\rm E}). For a fixed L>8​b∗/K∗L>8b^{*}/K_{*}, its response satisfies FE−z≥k​d2​z2F_{\rm E}-z\geq kd^{2}z^{2} on [L/d3,ε/d][L/d^{3},\varepsilon/d] and FE−z≥kF_{\rm E}-z\geq k on [ε/d,1/2][\varepsilon/d,1/2]. These are bounds for the numerator, before any denominator comparison. The response-error ratios in (38) are at most C/(n​z)≤C​d3/(L​n)=o⁡(1)C/(nz)\leq Cd^{3}/(Ln)=o(1) in the middle interval and O⁡(d2/n)=o⁡(1)O(d^{2}/n)=o(1) in the late interval, using only n/d3→∞n/d^{3}\to\infty. Thus q⁡(t)>t/nq(t)>t/n at every grid point outside [0,L/d3][0,L/d^{3}]; their binomial barrier values are negative since 1−q⁡(t)>01-q(t)>0.

On [0,L/d3][0,L/d^{3}], |FE(j)|=O⁡(dj)|F_{\rm E}^{(j)}|=O(d^{j}) for 2≤j≤52\leq j\leq 5, FE′=O⁡(1)F_{\rm E}^{\prime}=O(1), and P′′=−KE​(1+O⁡(d−2))P^{\prime\prime}=-K_{\rm E}(1+O(d^{-2})). The Taylor calculation already proved therefore gives zP≍d−3z_{P}\asymp d^{-3}, αE,Pois≍d−4\alpha_{{\rm E},{\rm Pois}}\asymp d^{-4} and the full exact-coefficient expansion. Expanding

AEquad=c22​d4​[1+2d+4−2​cd2+O⁡(d−3)]A_{\rm E}^{\rm quad}=\frac{c^{2}}{2d^{4}}\left[1+\frac{2}{d}+\frac{4-2c}{d^{2}}+O(d^{-3})\right]

and adding −L3,EbE3/(6KE3)=c3/(3d6)+O(d−7)-L_{3,\rm E}b_{\rm E}^{3}/(6K_{\rm E}^{3})=c^{3}/(3d^{6})+O(d^{-7}) proves (35); the other terms start at order d−7d^{-7}.

Only on the localized interval do we compare denominators. There FE=O⁡(d−3)F_{\rm E}=O(d^{-3}) and, by (38), q=O⁡(d−3)q=O(d^{-3}) at grid points, so both denominators are 1−O⁡(d−3)1-O(d^{-3}). The exact identity

z−q⁡(t)1−q⁡(t)−P⁡(z)=−(1−z)​(q⁡(t)−FE​(z))(1−q⁡(t))​(1−FE​(z))\frac{z-q(t)}{1-q(t)}-P(z)=-\frac{(1-z)(q(t)-F_{\rm E}(z))}{(1-q(t))(1-F_{\rm E}(z))}

then bounds the difference by C3/(n​d)C_{3}/(nd). Choose an integer tPt_{P} nearest to n​zPnz_{P}. Since n/d3→∞n/d^{3}\to\infty, its grid point is interior to the early interval and to [0,⌊n/2⌋/n][0,\lfloor n/2\rfloor/n]. Stationarity P′​(zP)=0P^{\prime}(z_{P})=0 and |P′′|=O⁡(d2)|P^{\prime\prime}|=O(d^{2}) give

P⁡(tP/n)=αE,Pois+O⁡(d2/n2).P(t_{P}/n)=\alpha_{{\rm E},{\rm Pois}}+O(d^{2}/n^{2}).

Both 1/(n​d)1/(nd) and d2/n2d^{2}/n^{2} are o⁡(d−4)o(d^{-4}). Thus this grid point has positive binomial barrier value; the binomial maximum is early. Comparison at this point gives the lower bound in (36), and comparison at a binomial maximiser gives its upper bound. No uniqueness of the integer maximiser is required.

Combining with (35) proves (37). Under d5/n→0d^{5}/n\to 0, d8/n2=(d5/n)2/d2→0d^{8}/n^{2}=(d^{5}/n)^{2}/d^{2}\to 0, proving the o⁡(d−6)o(d^{-6}) assertion. If d6=O⁡(n)d^{6}=O(n), then (n​d)−1=O⁡(d−7)(nd)^{-1}=O(d^{-7}) and d2/n2=O⁡(d−10)d^{2}/n^{2}=O(d^{-10}). If d8=O⁡(n)d^{8}=O(n), these errors are respectively O⁡(d−9)O(d^{-9}) and O⁡(d−14)O(d^{-14}), which proves the full-expansion assertion. ∎

The integer-time error O⁡(d2/n2)O(d^{2}/n^{2}) is distinct from rounding the number of seeds. For an integer seed size aa and α=a/n\alpha=a/n, the exact mean drift is

a+(n−a)​q​(t)−tn=(1−q⁡(t))​(α−t/n−q⁡(t)1−q⁡(t)).\frac{a+(n-a)q(t)-t}{n}=(1-q(t))\left(\alpha-\frac{t/n-q(t)}{1-q(t)}\right).

Consequently the smallest integer aa making all these mean drifts nonnegative is ⌈n​βn⌉\lceil n\beta_{n}\rceil; for strictly positive mean drifts it is ⌊n​βn⌋+1\lfloor n\beta_{n}\rfloor+1. Their density errors are respectively less than 1/n1/n and at most 1/n1/n. This additional seed-rounding error is not part of (36) or (37). All these barriers concern exact deterministic means on the stated time interval. They do not locate the random critical-window centre or justify shrinking relative margins in the probability theorems.

7 Scope

The results concern independent uniform seeds of prescribed size, fixed positive model parameters and fixed relative margins. They establish almost complete activation, not full activation, and do not identify optimal seeds or a shrinking critical window. The prescribed assumptions impose bounded degree deviations and a fixed positive excess-degree gap; they do not cover arbitrary heavy-tailed degrees or thresholds correlated with the graph.

For prescribed degrees the local concentration exponent n/d5n/d^{5} must dominate the O⁡(d2)O(d^{2}) simplicity cost and the logarithm of the grid factor; d=o⁡(n1/7)d=o(n^{1/7}) also controls the separate late estimate. For independent edges the maximal empirical-process estimate and dyadic budgets give passage failure O⁡(d5/n)O(d^{5}/n), so d5/n→0d^{5}/n\to 0 suffices. These are sufficient ranges, not optimal endpoints.

The explicit residuals tend to zero as fractions of nn for every allowed sequence with d→∞d\to\infty.

Corollary 5 gives sufficient logarithmic conditions for an O⁡(n2/3)O(n^{2/3}) inactive remainder. They are not necessity claims: Appendix B also gives this remainder in the prescribed slow-degree regime d​log⁡d=o⁡(log⁡n)d\log d=o(\log n). That adaptation does not establish the independent-edge counterpart or complete the subcritical terminal comparison with Rossi et al.

The finite-degree results are deterministic response statements. For the integer-time binomial barrier the three-term expansion has absolute remainder O⁡(d−7+(n​d)−1+d2/n2)O(d^{-7}+(nd)^{-1}+d^{2}/n^{2}), which is o⁡(d−6)o(d^{-6}) throughout the independent-edge theorem’s range. Rounding the number of seeds adds a separate density error O⁡(1/n)O(1/n). Neither error is a stochastic window estimate.

If c+1−vnc+1-v_{n} approaches zero, the exact identity in (11) shows that the order and sign of bb require a separate analysis. No boundary-gap conclusion is asserted here. An empty seed set remains empty because all thresholds are positive.

Appendix A Local concentration for the prescribed exploration

We prove Lemma 8, retaining the fixed-size seed law. For independent centred variables of absolute value at most BB and total variance at most VV, we use the two-sided bound 2exp[−x2/(2(V+Bx/3))]2\exp[-x^{2}/(2(V+Bx/3))]. For a martingale starting at zero, the same bound applies to its running absolute maximum if its jumps are bounded by BB and its predictable quadratic variation is at most VV. These follow from et−1−t≤t2/[2​(1−|t|/3)]e^{t}-1-t\leq t^{2}/[2(1-|t|/3)] for |t|<3|t|<3, the associated exponential (super)martingale, and the choice λ=x/(V+B​x/3)\lambda=x/(V+Bx/3); applying both signs gives the factor two. The martingale bound is applied only to stopped processes with a deterministic quadratic-variation bound.

One-vertex loss and the seed mean.

At fixed uu, put z=1−e−uz=1-e^{-u} and let X∼Bin⁡(k,z)X\sim\operatorname{Bin}(k,z) be independent of RR. For Y=(k−X)𝟏{X<R}Y=(k-X)\mathbf{1}_{\{X<R\}}, write

L=k−Y=k𝟏{X≥R}+𝟏{R=2,X=1}.L=k-Y=k\mathbf{1}_{\{X\geq R\}}+\mathbf{1}_{\{R=2,X=1\}}.

The two events are disjoint: activation loses all kk ends, and a threshold-two vertex with one mark loses one. Hence

Var⁡Y≤𝔼​L2=k2​[π​Pr⁡(X≥1)+(1−π)​Pr⁡(X≥2)]+(1−π)​Pr⁡(X=1)≤π​k3​z+k​z+k4​z2/2,\operatorname{Var}Y\leq\mathbb{E}L^{2}=k^{2}[\pi\Pr(X\geq 1)+(1-\pi)\Pr(X\geq 2)]+(1-\pi)\Pr(X=1)\leq\pi k^{3}z+kz+k^{4}z^{2}/2,

using Pr⁡(X≥1),Pr⁡(X=1)≤k​z\Pr(X\geq 1),\Pr(X=1)\leq kz and Pr⁡(X≥2)≤k2​z2/2\Pr(X\geq 2)\leq k^{2}z^{2}/2. Conditionally on a fixed seed set, different vertex summands are independent and lie in [0,Δ][0,\Delta]. Thus

Var⁡(H⁡(u)∣A0)≤V⁡(z):=min⁡{3​n​[(π​Δ3+Δ)​z+Δ4​z2/2],n​Δ2}.\operatorname{Var}(H(u)\mid A_{0})\leq V(z):=\min\{3n[(\pi\Delta^{3}+\Delta)z+\Delta^{4}z^{2}/2],\ n\Delta^{2}\}. (39)

Let gi​(u)=𝔼​Yi​(u)∈[0,Δ]g_{i}(u)=\mathbb{E}Y_{i}(u)\in[0,\Delta] and mA0​(u)=∑i∉A0gi​(u)m_{A_{0}}(u)=\sum_{i\notin A_{0}}g_{i}(u). Reveal the aa seed labels in random order without replacement. For a<na<n the Doob increment of the sampled sum at draw jj is

n−an−j​(gIj​(u)−g¯j−1​(u)),1≤j≤a,\frac{n-a}{n-j}\bigl(g_{I_{j}}(u)-\bar{g}_{j-1}(u)\bigr),\qquad 1\leq j\leq a,

where g¯j−1\bar{g}_{j-1} averages the labels not yet drawn. This follows by writing the expected remaining sample as a−ja-j times its remaining population mean. Its absolute value is at most Δ\Delta, so the bounded-increment exponential estimate gives

Pr{|mA0(u)−H¯(u)|>e}≤2e−e2/(2aΔ2).\Pr\{|m_{A_{0}}(u)-\bar{H}(u)|>e\}\leq 2e^{-e^{2}/(2a\Delta^{2})}. (40)

For a=0,na=0,n the discrepancy is zero. The same estimate includes the variation in seed degrees at u=0u=0. For the reference sizes, a​Δ2=O⁡(n/d2)a\Delta^{2}=O(n/d^{2}).

Stopped queue martingale.

Use the exploration filtration, which does not reveal future clocks of manually removed ends. If JJ counts pairings through τ\tau, its compensator is ∫0u∧τW⁡(s−)​𝑑s\int_{0}^{u\wedge\tau}W(s-)\,ds: before stopping there are WW unreserved rate-one clocks. The fictitious terminal reservation makes every jump of WW exactly −2-2, also at τ\tau. Consequently

Z(u)=e2​(u∧τ)W(u∧τ)−(M−1)=−2∫0u∧τe2​s(dJ(s)−W(s−)ds)Z(u)=e^{2(u\wedge\tau)}W(u\wedge\tau)-(M-1)=-2\int_{0}^{u\wedge\tau}e^{2s}(dJ(s)-W(s-)\,ds)

is a martingale. For each deterministic r≤Ur\leq U,

|Δ​Z|≤2​e2​r,⟨Z⟩r=4​∫0r∧τe4​s​W​(s−)​𝑑s≤4​e4​r​M​r.|\Delta Z|\leq 2e^{2r},\qquad\langle Z\rangle_{r}=4\int_{0}^{r\wedge\tau}e^{4s}W(s-)\,ds\leq 4e^{4r}Mr.

The value W⁡(τ)W(\tau) may be −1-1 if the pairing is exhausted, but the intensity uses the nonnegative preterminal value W⁡(s−)W(s-). The martingale inequality therefore gives

Pr{supu≤r∧τ|W(u)−Me−2​u|>e+1}≤pW(e,r):=2exp[−e22​(4​e4​r​M​r+2​e2​r​e/3)].\Pr\left\{\sup_{u\leq r\wedge\tau}|W(u)-Me^{-2u}|>e+1\right\}\leq p_{W}(e,r):=2\exp\left[-\frac{e^{2}}{2(4e^{4r}Mr+2e^{2r}e/3)}\right]. (41)

The extra one accounts for W⁡(0)=M−1W(0)=M-1.

Time interpolation.

For any deterministic interval I=[l,r]⊂[0,U]I=[l,r]\subset[0,U] and e≥1e\geq 1, use a grid containing both endpoints with mesh at most e/(4​n​Δ2)e/(4n\Delta^{2}). Its size is at most NI=⌈4​(r−l)​n​Δ2/e⌉+1N_{I}=\lceil 4(r-l)n\Delta^{2}/e\rceil+1 (one point for a degenerate interval). At a grid point, conditional Bernstein and (40) give |H−H¯|≤2​e|H-\bar{H}|\leq 2e, except with probability at most

2exp[−e22​(V⁡(1−e−r)+Δ​e/3)]+2exp[−e2/(2aΔ2)].2\exp\left[-\frac{e^{2}}{2(V(1-e^{-r})+\Delta e/3)}\right]+2\exp[-e^{2}/(2a\Delta^{2})].

Each Yi​(u)Y_{i}(u) is nonincreasing. Its clock-event rate is at most did_{i} and each loss at most did_{i}, whence |gi′​(u)|≤di2|g_{i}^{\prime}(u)|\leq d_{i}^{2}. Thus both HH and H¯\bar{H} are nonincreasing and |H¯′|≤n​Δ2|\bar{H}^{\prime}|\leq n\Delta^{2}. Bracketing an intermediate value of HH by its two adjacent grid values, and varying the mean by at most e/4e/4, gives |H−H¯|≤9​e/4|H-\bar{H}|\leq 9e/4 on all of II, including jumps. Combining with (41) yields

|Q−Dα|≤4​e+1on ​I∩[0,τ],|Q-D_{\alpha}|\leq 4e+1\quad\hbox{on }I\cap[0,\tau], (42)

except on an event of probability at most

pW(e,r)+NI{2exp[−e22​(V⁡(1−e−r)+Δ​e/3)]+2exp[−e2/(2aΔ2)]}.p_{W}(e,r)+N_{I}\left\{2\exp\left[-\frac{e^{2}}{2(V(1-e^{-r})+\Delta e/3)}\right]+2\exp[-e^{2}/(2a\Delta^{2})]\right\}.

This is a union bound, with no independence between intervals, between WW and HH, or between the estimates and survival.

Three scales and the total passage probability.

Partition the zz interval into [0,L/d3][0,L/d^{3}], dyadic intervals [s,min⁡(2​s,η/d)][s,\min(2s,\eta/d)] starting at s=L/d3s=L/d^{3}, and [η/d,1/2][\eta/d,1/2]. Map them to u=−log⁡(1−z)u=-\log(1-z) and choose budgets respectively

e0=ρ​n/d3,es=ρ​n​d3​s2,ep=ρ​n​d.e_{0}=\rho n/d^{3},\qquad e_{s}=\rho nd^{3}s^{2},\qquad e_{\rm p}=\rho nd.

Fix ρ>0\rho>0 sufficiently small relative to (15). The minimum budget tends to infinity, so 4​e+14e+1 is smaller than half the appropriate margin, including the negative test at u∗u_{*}. On the early interval, (39) is O⁡(n/d)O(n/d), a​Δ2=O⁡(n/d2)a\Delta^{2}=O(n/d^{2}) and M​r=O⁡(n/d2)Mr=O(n/d^{2}). The three exponents (vertex Bernstein, seed, queue) are therefore bounded below by constant multiples of n/d5,n/d4,n/d4n/d^{5},n/d^{4},n/d^{4}.

On a middle interval r=O⁡(s)r=O(s) and zr≤2​sz_{r}\leq 2s. The corresponding exponents have the lower bounds

k​n​d4​s31+d2​s,k​n​d8​s4,k​n​d5​s31+d2​s,k\frac{nd^{4}s^{3}}{1+d^{2}s},\qquad knd^{8}s^{4},\qquad k\frac{nd^{5}s^{3}}{1+d^{2}s},

respectively. Here V⁡(zr)+Δ​es≤C​n​(d2​s+d4​s2)V(z_{r})+\Delta e_{s}\leq Cn(d^{2}s+d^{4}s^{2}) and M​r+es≤C​n​d​s​(1+d2​s)Mr+e_{s}\leq Cnds(1+d^{2}s). Since s3/(1+d2​s)s^{3}/(1+d^{2}s) is increasing and s≥L/d3s\geq L/d^{3}, these bounds are at least constant multiples of n/d5,n/d4,n/d4n/d^{5},n/d^{4},n/d^{4}. On the last interval use V≤n​Δ2V\leq n\Delta^{2}: all three exponents are at least k​nkn. This last budget is for passage only.

The early grid has O⁡(1+d2)O(1+d^{2}) points; a middle grid has O⁡(1+1/(d​s))=O⁡(1+d2)O(1+1/(ds))=O(1+d^{2}) points; the late grid has O⁡(1+d)O(1+d) points. There are O⁡(1+log⁡d)O(1+\log d) intervals, because the ratio of the middle endpoints has order d2d^{2}. Summing (42)’s failure bounds proves (18). This completes the local estimate without a global error of order n2/3​dn^{2/3}d at the bottleneck.

Appendix B The slow-degree overlap with finite-time approximation

We record the adaptation used in the literature comparison, without introducing a separate threshold theorem. Fix c>0c>0, C≥0C\geq 0, κ>0\kappa>0 and γ∈(0,1)\gamma\in(0,1). The prescribed nonnegative integer degrees have even sum n​dnd, exact mean dd, and satisfy

|di−d|≤C​d,vn=1n​d​∑i(di−d)2,c+1−vn≥κ,d→∞,d​log⁡d=o⁡(log⁡n).|d_{i}-d|\leq C\sqrt{d},\qquad v_{n}=\frac{1}{nd}\sum_{i}(d_{i}-d)^{2},\qquad c+1-v_{n}\geq\kappa,\qquad d\to\infty,\quad d\log d=o(\log n).

Let pk=n−1​|{i:di=k}|p_{k}=n^{-1}|\{i:d_{i}=k\}|, δ=mini⁡di\delta=\min_{i}d_{i} and Δ=maxi⁡di\Delta=\max_{i}d_{i}. Independently of the graph, thresholds are independent with probabilities π=(1−c/d)/d\pi=(1-c/d)/d and 1−π1-\pi for one and two, and the seed is a uniform subset of deterministic size aa. With expectation taken under pkp_{k}, set

b=1−π​𝔼⁡[D⁡(D−1)]d,K=(1−2​π)​𝔼​[D​(D−1)​(D−2)]d,A=b22​K.b=1-\pi\frac{\mathbb{E}[D(D-1)]}{d},\qquad K=(1-2\pi)\frac{\mathbb{E}[D(D-1)(D-2)]}{d},\qquad A=\frac{b^{2}}{2K}.

Then b≍d−1b\asymp d^{-1}, K≍d2K\asymp d^{2}, and A≍d−4A\asymp d^{-4}, uniformly for the fixed parameters above. We show that a≥(1+γ)​n​Aa\geq(1+\gamma)nA implies n−|A∞|=O⁡(n2/3)n-|A_{\infty}|=O(n^{2/3}) with probability tending to one on the uniform simple graph. The probability includes the graph, thresholds and seed. Since n​A→∞nA\to\infty, it suffices by paragraph 2.1 to use a0=⌈(1+γ/2)​n​A⌉a_{0}=\lceil(1+\gamma/2)nA\rceil and α=a0/n\alpha=a_{0}/n.

On undirected trees the nonroot recursion excludes the parent edge, as in Lemma 4 of the accepted manuscript of Rossi et al. (2019).

The printed Theorem 2 refers to recursion (7), whose formulas (13)–(14) use kk rather than k−1k-1 trials. We therefore prove the finite-time estimate needed for the excess-degree recursion directly, following the coupling and concentration strategy of Section 4.2 of Rossi et al. (2019).

Lemma 14 (Finite-time approximation for an undirected pairing).

Fix degrees di≥0d_{i}\geq 0 with even sum M=n​d>0M=nd>0 and maximum Δ≥2\Delta\geq 2, and fix integer thresholds rir_{i} and labels sis_{i}, where si∈{0,1}s_{i}\in\{0,1\}, ri=0r_{i}=0 if si=1s_{i}=1, and ri≥1r_{i}\geq 1 otherwise. Let uk,r,s=n−1​|{i:(di,ri,si)=(k,r,s)}|u_{k,r,s}=n^{-1}|\{i:(d_{i},r_{i},s_{i})=(k,r,s)\}|. On a uniform pairing of the labelled half-edges, run synchronous progressive activation with these initial states and thresholds, counting edges with multiplicity, and let Zt=|At|/nZ_{t}=|A_{t}|/n. Set Bm,r(x)=Pr{Bin(m,x)≥r}B_{m,r}(x)=\Pr\{\operatorname{Bin}(m,x)\geq r\}, with Bm,0=1B_{m,0}=1 and Bm,r=0B_{m,r}=0 for r>mr>m, and define

fu​(x)=∑k≥1,r,sk​uk,r,sd​Bk−1,r​(x),gu​(x)=∑k,r,suk,r,s​Bk,r​(x),f_{u}(x)=\sum_{k\geq 1,r,s}\frac{ku_{k,r,s}}{d}B_{k-1,r}(x),\qquad g_{u}(x)=\sum_{k,r,s}u_{k,r,s}B_{k,r}(x),
x0=∑k,rk​uk,r,1d,y0=∑k,ruk,r,1,xj+1=fu​(xj),yj+1=gu​(xj).x_{0}=\sum_{k,r}\frac{ku_{k,r,1}}{d},\qquad y_{0}=\sum_{k,r}u_{k,r,1},\qquad x_{j+1}=f_{u}(x_{j}),\quad y_{j+1}=g_{u}(x_{j}).

For an integer t≥1t\geq 1, put

Qt=∑j=1tΔj,bt=Δ​Qt​(Qt+1)2​M.Q_{t}=\sum_{j=1}^{t}\Delta^{j},\qquad b_{t}=\frac{\Delta Q_{t}(Q_{t}+1)}{2M}.

If M≥2​Qt+2M\geq 2Q_{t}+2, then |𝔼​Zt−yt|≤bt|\mathbb{E}Z_{t}-y_{t}|\leq b_{t}. For every h>0h>0, without this size restriction,

Pr{|Zt−𝔼Zt|>h}≤2exp(−n​h2128​d​Δ2​t).\Pr\{|Z_{t}-\mathbb{E}Z_{t}|>h\}\leq 2\exp\left(-\frac{nh^{2}}{128d\Delta^{2t}}\right).

Consequently, if also bt≤ε/2b_{t}\leq\varepsilon/2, then

Pr{|Zt−yt|>ε}≤2exp(−n​ε2512​d​Δ2​t).\Pr\{|Z_{t}-y_{t}|>\varepsilon\}\leq 2\exp\left(-\frac{n\varepsilon^{2}}{512d\Delta^{2t}}\right).

All these bounds are uniform over the fixed labels. If instead the labels (ri,si)(r_{i},s_{i}) are iid, independently of the pairing, with law λr,s\lambda_{r,s}, the expectation bound holds with uk,r,s=pk​λr,su_{k,r,s}=p_{k}\lambda_{r,s}, where pk=n−1​|{i:di=k}|p_{k}=n^{-1}|\{i:d_{i}=k\}|. The concentration denominator becomes (128​d+8)​Δ2​t(128d+8)\Delta^{2t}, and the combined denominator becomes (512​d+32)​Δ2​t(512d+32)\Delta^{2t}. Here probability averages over pairing and labels.

Proof.

Choose a uniform root vertex. Its type has law uu. For each nonroot vertex of an independent comparison tree, choose a uniform half-edge from all MM half-edges, with replacement, and use the type of its incident vertex. These independent types have law k​uk,r,s/dku_{k,r,s}/d. The root has kk children and every nonroot vertex of degree kk has k−1k-1 children.

On a tree, removing the parent edge does not change a child’s contribution to the first activation of its parent: until that activation the parent has been inactive at all earlier times. Induction on time, applying this observation to each child subtree, therefore identifies the root state with the outward-oriented tree calculation. With seeds encoded by threshold zero, the states in this calculation are nondecreasing in time. Independent subtrees then give exactly the recursions above, and the root activation probability at time tt is yty_{t}.

Explore the pairing breadth first from the same root, exposing edges only from vertices at distance less than tt. At most QtQ_{t} partners are needed. After hh successful tree discoveries at most h+1h+1 vertices have been seen. Draw the next comparison half-edge UU uniformly from all MM half-edges. If it is an eligible partner for the current half-edge, use it in the pairing; otherwise choose a uniform eligible partner independently. This rule gives a uniform partner: every eligible half-edge has probability 1/|E|1/|E|, where EE is the eligible set. All ineligible half-edges belong to already seen vertices. Thus, until the first failure, if UU belongs to an unseen vertex, both constructions agree and discover a new vertex. Declare failure whenever UU belongs to a seen vertex. Its conditional probability is at most (h+1)​Δ/M(h+1)\Delta/M. The size assumption ensures that partners remain available during this exploration. A union bound gives failure probability at most

∑h=0Qt−1(h+1)​ΔM=bt.\sum_{h=0}^{Q_{t}-1}\frac{(h+1)\Delta}{M}=b_{t}.

Unexposed edges incident only to depth-tt vertices cannot affect the root state by time tt. Complete the remaining pairing uniformly. The coupled root states agree outside the failure event, proving the expectation bound.

For concentration, generate a uniform pairing by a uniform permutation of the MM half-edges and pair consecutive positions. A transposition changes at most two pairs and involves at most four endpoint vertices. A state at time tt can change only within distance t−1t-1 of those endpoints in at least one of the two graphs. Each such ball has at most ∑j=0t−1Δj≤Δt\sum_{j=0}^{t-1}\Delta^{j}\leq\Delta^{t} vertices. Hence the activation count changes by at most 8​Δt8\Delta^{t} under any transposition. This estimate also covers loops and repeated edges.

Expose the permutation one position at a time. Conditional completions for two possible next values are in bijection by transposing those values in the remaining positions. Their expected activation counts therefore differ by at most 8​Δt8\Delta^{t}. Each increment of the Doob martingale for |At||A_{t}| is bounded in absolute value by 8​Δt8\Delta^{t}. Azuma’s inequality, with at most MM increments, yields

Pr{||At|−𝔼|At||>nh}≤2exp(−n2​h22​M​(8​Δt)2),\Pr\{\big||A_{t}|-\mathbb{E}|A_{t}|\big|>nh\}\leq 2\exp\left(-\frac{n^{2}h^{2}}{2M(8\Delta^{t})^{2}}\right),

which is the stated concentration estimate. Taking h=ε/2h=\varepsilon/2 and using the expectation bound proves the last assertion. For iid labels, the same breadth-first coupling assigns each newly discovered vertex’s fresh independent label to its tree occurrence; at the first repeated vertex, assign that occurrence a fresh independent label and fill the rest of the comparison tree independently. Discovery order does not use labels, so this gives mean type law pk​λr,sp_{k}\lambda_{r,s} and the same bias btb_{t}.

For concentration expose the pairing permutation and then the independent labels. Changing one label affects only its radius-tt ball, of size at most ∑j=0tΔj≤2​Δt\sum_{j=0}^{t}\Delta^{j}\leq 2\Delta^{t}. The additional nn martingale increments are therefore bounded by 2​Δt2\Delta^{t}. The squared increment budget is (64​M+4​n)​Δ2​t(64M+4n)\Delta^{2t}; Azuma gives denominator (128​d+8)​Δ2​t(128d+8)\Delta^{2t}. Taking h=ε/2h=\varepsilon/2 gives the combined bound. ∎

Initially use iid Bernoulli(α)(\alpha) seeds, independently of the thresholds and pairing. The mean tree maps are

fα​(x)=α+(1−α)​FP​(x),f_{\alpha}(x)=\alpha+(1-\alpha)F_{\rm P}(x),
gα​(x)=1−(1−α)​∑kpk​[(1−x)k+(1−π)​k​x​(1−x)k−1].g_{\alpha}(x)=1-(1-\alpha)\sum_{k}p_{k}\big[(1-x)^{k}+(1-\pi)kx(1-x)^{k-1}\big].

Set x0=y0=αx_{0}=y_{0}=\alpha, xt+1=fα​(xt)x_{t+1}=f_{\alpha}(x_{t}) and yt+1=gα​(xt)y_{t+1}=g_{\alpha}(x_{t}).

Lemma 7 applies to the mean P response and α=(1+γ/2)​A+o⁡(A)\alpha=(1+\gamma/2)A+o(A). The increments fα​(x)−xf_{\alpha}(x)-x are at least k​d−4kd^{-4} up to L/d3L/d^{3}, k​d2​x2kd^{2}x^{2} up to ε/d\varepsilon/d, and kk up to 1/21/2. The first interval takes O⁡(d)O(d) steps. Crossing each dyadic [s,2​s][s,2s] takes at most 1+C/(d2​s)1+C/(d^{2}s) steps. Their sum is O⁡(d)O(d), since ss starts at L/d3L/d^{3} and ∑j2−j<∞\sum_{j}2^{-j}<\infty. The remaining interval takes O⁡(1)O(1) steps. Thus a fixed L0L_{0} gives xT0≥1/2x_{T_{0}}\geq 1/2 for T0=⌈L0​d⌉T_{0}=\lceil L_{0}d\rceil.

For qt=1−xt≤1/2q_{t}=1-x_{t}\leq 1/2, the displayed responses imply, eventually,

qt+1≤(1+Δ)​qtδ−2≤qtδ/2,1−gα​(xt)≤(1+Δ)​qtδ−1≤qtδ/2.q_{t+1}\leq(1+\Delta)q_{t}^{\delta-2}\leq q_{t}^{\delta/2},\qquad 1-g_{\alpha}(x_{t})\leq(1+\Delta)q_{t}^{\delta-1}\leq q_{t}^{\delta/2}.

The second inequalities use log⁡(1+Δ)=o⁡(δ)\log(1+\Delta)=o(\delta), and remain valid at qt=0q_{t}=0. Choose

r=max⁡{0,⌈log⁡((log⁡n)/(3​log⁡2))log⁡(δ/2)⌉},T=T0+r+1.r=\max\left\{0,\left\lceil\frac{\log((\log n)/(3\log 2))}{\log(\delta/2)}\right\rceil\right\},\qquad T=T_{0}+r+1.

Then 1−yT≤n−1/31-y_{T}\leq n^{-1/3} and T​log⁡(Δ+1)=O⁡(d​log⁡d+log⁡log⁡n)=o⁡(log⁡n)T\log(\Delta+1)=O(d\log d+\log\log n)=o(\log n).

Apply the iid-label part of Lemma 14 at t=Tt=T with ε=n−1/3\varepsilon=n^{-1/3}. Since QT≤2​ΔT=no⁡(1)Q_{T}\leq 2\Delta^{T}=n^{o(1)}, eventually n​d≥2​QT+2nd\geq 2Q_{T}+2 and bT=n−1+o⁡(1)≤ε/2b_{T}=n^{-1+o(1)}\leq\varepsilon/2. The failure probability is at most

2​exp⁡[−n1/3(512​d+32)​Δ2​T].2\exp\left[-\frac{n^{1/3}}{(512d+32)\Delta^{2T}}\right].

Condition now on exactly a0a_{0} seeds and on simplicity. The seed count a0a_{0} is a mode of Bin⁡(n,a0/n)\operatorname{Bin}(n,a_{0}/n), with probability at least 1/(n+1)1/(n+1); its conditioning gives uniform seeds of size a0a_{0}. Pairing and labels are independent, so the threshold law remains iid and independent of these seeds and the uniform simple graph. The McKay–Wormald estimate from Section 3 applies in the slow range and gives sn≥e−C0​d2>0s_{n}\geq e^{-C_{0}d^{2}}>0, also proving graphicality. The resulting total failure is at most

2​(n+1)​exp⁡[C0​d2−n1/3(512​d+32)​Δ2​T]=o⁡(1),2(n+1)\exp\left[C_{0}d^{2}-\frac{n^{1/3}}{(512d+32)\Delta^{2T}}\right]=o(1),

because d=no⁡(1)d=n^{o(1)}, Δ2​T=no⁡(1)\Delta^{2T}=n^{o(1)}, and the negative exponent dominates both d2d^{2} and log⁡(n+1)\log(n+1). On the good event n−|AT|≤2​n2/3≤3​n2/3n-|A_{T}|\leq 2n^{2/3}\leq 3n^{2/3}. Permanent activation gives AT⊆A∞A_{T}\subseteq A_{\infty}, proving the remainder. This argument establishes no subcritical terminal upper bound and does not apply unchanged to the independent-edge model.

Author disclosure

The author is employed by Yandex. This research was conducted independently in the author’s personal time and received no dedicated funding from Yandex. Some computational work used Yandex equipment and computing infrastructure. The views expressed are solely those of the author and do not necessarily represent those of Yandex. The author declares no other competing interests.

AI assistance

OpenAI’s GPT-6 Astra agents were used as research assistants for literature analysis, mathematical calculations and proof arguments, and manuscript preparation. OpenResearch was used to organize research tasks, experiments, and artifacts. These tools do not replace independent human peer review. The author is responsible for all mathematical results and the final manuscript.

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