Back to search
2203.00785

Back to Boundaries in Billiards

Leonid Bunimovich, Yaofeng Su

correcthigh confidence
Category
Not specified
Journal tier
Strong Field
Processed
Sep 28, 2025, 12:56 AM

Audit review

The paper proves a Poisson point-process limit for boundary holes in billiard systems under a CMZ (Chernov–Markarian–Zhang) inducing structure and geometric transversality (Assumption 2.11), via a multi-stage argument: reduction from quasi-sections to sections, inducing to truncated/thickened Young towers, control of short returns, and a Poisson approximation on (generally non-mixing) hyperbolic towers, then lifting back to the original system (Theorem 2.13) . The candidate solution outlines the same rare-events scheme (sections → inducing → short-return bounds → block/mixing control → Chen–Stein Poisson approximation → lifting), but it relies on a more classical Chen–Stein approach on the induced system and does not build the "thicker" non-mixing towers that are central to the paper’s treatment of arbitrarily slow mixing. Still, the model’s outline is directionally correct and compatible with the paper’s goals; it differs in technique and omits several novel technical devices of the paper (notably the tower thickening and the specific short-return estimates on X), hence they are both correct but use different proofs.

Referee report (LaTeX)

\textbf{Recommendation:} minor revisions

\textbf{Journal Tier:} strong field

\textbf{Justification:}

The paper achieves a broad Poisson limit theorem for boundary holes across multiple billiard families, leveraging a CMZ structure plus novel thickened Young towers and a careful short-return analysis. These ideas remove restrictive correlation-rate assumptions and extend applicability to slowly mixing regimes. The proof is long but coherent; a few expository enhancements would further improve readability.