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2508.13420

On subshifts with low maximal pattern complexity

Anh N. Le, Ronnie Pavlov, Casey Schlortt

correctmedium confidence
Category
math.DS
Journal tier
Strong Field
Processed
Sep 28, 2025, 12:57 AM

Audit review

The uploaded paper proves that pattern Sturmian sequences (defined by p* x(n)=2n for all n) are exactly of two types in the recurrent case—recurrent simple circle rotation codings or nearly simple Toeplitz—and, in the nonrecurrent case, are either nonrecurrent simple circle codings or almost constant. These are Theorems A and B in the PDF and are derived via the MEF analysis and structural results for non‑superlinear maximal pattern complexity (Theorems C and D and subsequent propositions). The candidate solution reproduces this classification, explicitly corrects the 2^n→2n typo, and follows the same proof skeleton (circle/odometer MEF, 1‑hole Toeplitz⇒nearly simple Toeplitz, exclusion of nearly simple Toeplitz in the nonrecurrent orbit closure, and characterization of nonrecurrent circle codings). In particular, the definitions (Definition 2.8), the main classification (Theorems A and B), and the key lemmas and propositions used (e.g., Propositions 4.7, 4.8, 5.2; Theorem 6.1; Lemma 6.5; Proposition 6.6; and Proposition 2.11) align point‑for‑point with the paper’s argument. Therefore, both are correct and the proofs are substantially the same, with the model’s write‑up serving as a concise restatement grounded in the paper’s framework. Citations: definition and setup ; main theorems A–B ; circle×finite MEF reduction and circle coding structure , , ; exclusion of nearly simple Toeplitz in the nonrecurrent case ; almost‑constant alternative and periodic closure obstruction ; nonrecurrent circle coding characterization .

Referee report (LaTeX)

\textbf{Recommendation:} minor revisions

\textbf{Journal Tier:} strong field

\textbf{Justification:}

This work provides a definitive classification of recurrent pattern Sturmian sequences and a near-complete treatment of the nonrecurrent case, answering a question posed by Kamae–Zamboni. The approach, via MEF analysis and careful use of Toeplitz classification, is conceptually clean and likely to be influential in related low-complexity dynamical systems questions. The exposition is clear, with well-organized preliminaries and a logical flow; a few minor clarifications would further enhance readability.