2409.01261
DISTRIBUTIONS OF PERIODIC POINTS FOR THE DYCK SHIFT AND THE HETEROCHAOS BAKER MAPS
Hiroki Takahasi
correctmedium confidence
- Category
- math.DS
- Journal tier
- Strong Field
- Processed
- Sep 28, 2025, 12:56 AM
- arXiv Links
- Abstract ↗PDF ↗
Audit review
The paper proves Theorems 1.1–1.2 by coding the heterochaos baker map to the Dyck shift π(Λ)=Σ_D (not an SFT) and then transporting periodic-point statistics through Krieger’s conjugacies with two full shifts Σ_α, Σ_β. It uses Kifer’s large-deviation machinery to show that periodic points with H_n>0 (resp. H_n<0) equidistribute to ν_α (resp. ν_β), and finally pulls this back to μ_α, μ_β for the baker map; it also shows #Per_{α,n}=#Per_{β,n} via an exact symmetry/counting identity (2.5) and (2.6) (Theorem 1.1 and its Dyck-shift counterpart Theorem 1.2) . By contrast, the model’s solution incorrectly asserts a one-step mixing SFT coding with specific local adjacency rules, whereas the correct coding is the Dyck shift (not SFT) defined by balanced-bracket constraints . The model then invokes equidistribution and constrained variational principles for mixing SFTs; these do not apply as stated to the Dyck shift, and the claimed “Markov partition” and SFT adjacency are unsupported and contradicted by the paper’s π(Λ)=Σ_D identification. The model also mischaracterizes the excluded H_n=0 class as “subexponential,” whereas the paper gives its exact exponential growth with smaller rate via Hamachi–Inoue (2.6)–(2.9) . In short, the paper’s result and proof are sound, while the model rests on a false SFT premise and misapplied tools.
Referee report (LaTeX)
\textbf{Recommendation:} minor revisions \textbf{Journal Tier:} strong field \textbf{Justification:} The paper addresses a clean and timely question: how coexisting MMEs are reflected in the distribution of periodic points by unstable index for a canonical partially hyperbolic model (heterochaos baker maps) and for the Dyck shift. The strategy—coding to the Dyck shift, invoking Krieger’s conjugacies with two full shifts, applying Kifer’s large deviations to periodic points, and transporting back—is well chosen and effectively executed. The results (Theorems 1.1–1.2) are correct and clearly situated in the literature. Minor clarifications could further help readers (e.g., the role of non-separated periodic sets and how the large-deviation upper bound yields concentration).