arXiv:2607.27932v2
Abstract
The present work investigates the asymptotic behaviours at the zero-noise limit of the first near collision-time and first near collision-location between a pair of independent -dimensional Brownian-driven self-stabilizing (McKean-Vlasov type) diffusions. These asymptotic are considered in a peculiar setting where the systems evolve in a bi-stable landscape and collisions are only triggered by the combined action of the Brownian noises. As the Brownian perturbations fade away, we show that the near collision-time increases at an explicit exponential rate and that related collision-locations persist in specific regions of the space. These results are mainly derived by tailoring classical Freidlin-Wentzell's exit-time (and exit-location) estimates into collision estimates. Similar asymptotic are established for related mean-field interacting particle system approximation, and for the one-dimensional case (where true collisions can be examined
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Not a correctness certificate. A “Correct” result may include yellow typos or minor formal corrections that do not affect substantive soundness. It means this audit found no unresolved substantive error under the stated criteria; it does not replace expert scrutiny or formal verification.
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Detailed mathematical audit
01Statements2 reported findingsContains unsupported statements
No counterexample to either principal collision law was established. Both remain unverified under the printed assumptions, however. The proof applies the paper's bounded-domain, globally-Lipschitz Freidlin--Wentzell theorem to unbounded domains and polynomial drifts, and its exponentially long coupling uses a local quadratic stability property that does not follow from asymptotic stability. The particle theorem also requires a population threshold depending on the collision radius, while its statement quantifies over one fixed sufficiently large population before taking the radius to zero.
Collision law for the two self-stabilizing diffusions
Pages 9 and 13–28 · Theorem 1.5 and Sections 2–3 · arXiv:2607.27932v2
The action is the natural candidate for the iterated small-radius and small-noise collision cost, and the finite-cover argument would transfer fixed-center hitting laws to the first collision. Two indispensable inputs are not established under Assumptions (A), though. First, Lemma 2.2 invokes Theorem 1.4 outside the theorem's printed bounded-domain and globally-Lipschitz hypotheses. Second, Proposition 3.2 assumes local quadratic attraction of at each well, whereas (A)-(ii) gives only Lyapunov asymptotic stability. Since these inputs control the process for times of order , the displayed double limit and persistence conclusion are not verified by the present proof. This is not a claim that the theorem is false.
Collision law for a fixed sufficiently large particle population
Pages 10 and 29–35 · Theorem 1.6 and Section 4 · arXiv:2607.27932v2
This theorem inherits the unresolved Freidlin--Wentzell and local-stability inputs from Theorem 1.5. It also states the iterated limit for every fixed above one unspecified threshold. Proposition 4.2 instead produces depending on the collision radius and coupling tolerance; the transfer to a radius- hitting event requires the tolerance to be smaller than . No uniform bound on as is proved. The argument therefore verifies, at most, a formulation in which is chosen after fixing , not the printed quantifier order.
02Proofs6 reported findingsContains incorrect or incomplete proofs
The finite-cover reductions and many coupling estimates are internally consistent after local notation corrections, but three central obligations remain: extending the exit theorem to the unbounded polynomial-drift setting actually used, justifying exponentially long localization from the stated stability assumption, and making the particle-rank choice uniform in the outer radius limit. The printed definition of the positive small-radius threshold also uses an infimum where its own explanation requires a supremal interval.
The recalled exit theorem is applied outside two explicit hypotheses
Pages 8 and 13–17 · Theorem 1.4 and Lemmas 2.2–2.4 · arXiv:2607.27932v2
Theorem 1.4 in the paper assumes an open bounded exit domain and globally Lipschitz drift and diffusion. Lemma 2.2 applies it to and its modified versions. These domains are generally unbounded; for the one-dimensional contractive drift , each complement is already an unbounded half-line when the target ball misses . Moreover, the main drifts have the polynomial growth allowed by (A)-(i) and (A)-(iii), not global Lipschitz continuity. No extension theorem or truncation-and-outer-boundary argument is supplied. Downstream dependency: Lemma 2.4, Propositions 2.5, 3.3–3.4, and both main theorems. A repair must prove an unbounded-domain exit law under the paper's coercive polynomial hypotheses or truncate the domains and show uniformly that every artificial outer boundary has strictly larger action.
Asymptotic stability is used as if it implied quadratic local coercivity
Pages 26–27 · Step 4 of Proposition 3.2 · arXiv:2607.27932v2
The proof asserts that the Jacobian of at is negative definite and hence that, for some , lies in Assumption (A)-(ii) states only Lyapunov asymptotic stability. That does not imply hyperbolicity or this quadratic bound: the scalar flow is asymptotically stable at zero but satisfies , which cannot dominate near zero. The other assumptions do not add the asserted property for itself. This bound is then used to keep small up to exponentially large times. A verified sufficient repair is to assume explicitly that in a neighborhood of each well, or replace Step 4 by a localization argument valid for nonhyperbolic stable equilibria.
The population threshold is not uniform in the radius limit
Pages 10 and 29–35 · Theorem 1.6, Proposition 4.2, and Section 4.2 · arXiv:2607.27932v2
Theorem 1.6 first fixes a sufficiently large and then takes . Proposition 4.2 chooses after and , and the bracketing of radius- hitting times requires . The proof gives no bound on . Repair classification: unresolved under the printed theorem. Either establish such a uniform bound, or change the conclusion to state the fixed- law with and specify a joint order of limits.
An infimum cannot define the advertised largest small-radius interval
Pages 17 and 27 · definitions preceding Propositions 2.5 and 3.4 · arXiv:2607.27932v2
Both definitions print as the infimum of radii at which the desired strict comparison holds, then call it the largest radius and use the comparison for every . If the comparison holds for all sufficiently small radii, the printed infimum is zero. The definition dictated by the following prose is This symbol-level correction does not change the intended results, but the proof must still verify that this set contains a positive interval.
Four local symbols conflict with their immediately stated meaning
Pages 5, 22, and 24 · (A)-(i), (A)-(ii), and Proposition 3.2 · arXiv:2607.27932v2
The strong-convexity inequality in (A)-(i) is printed with although the subsequent deductions require ; (A)-(ii) writes for both wells instead of . In Proposition 3.2, and the force estimate use where their dependence on the running time and every later line require . These replacements are uniquely determined by the surrounding logic and are treated as typos, not adverse statement findings.
A product probability is used despite interacting particles
Page 33 · Step 5.2.3 of Proposition 4.2 · arXiv:2607.27932v2
The proof bounds the probability that at least tagged couplings fail by a binomial sum involving . The failure events are not independent because the interact through their empirical measure, so the product power is unjustified. Repair classification: verified repair. Exchangeability and Markov's inequality give which supplies exactly the high-probability conclusion needed in the following step.
03Novelty0 reported findingsNo non-novelty findings
No non-novelty findings.