2411.10749
LOWERING MEAN TOPOLOGICAL DIMENSION
Ruxi Shi
correctmedium confidence
- Category
- Not specified
- Journal tier
- Specialist/Solid
- Processed
- Sep 28, 2025, 12:56 AM
- arXiv Links
- Abstract ↗PDF ↗
Audit review
The paper proves Theorem 1.2 via Proposition 5.1: for fixed ε,δ it constructs a factor with mdim(Y)<δ and per-block relative width-dimension bounded by <δ, and then passes to an infinite product to achieve mdim(π,T)=0 (see Theorem 1.2 and the reduction via Proposition 5.1) . The candidate solution matches the paper through the tiling construction (Proposition 3.1), the width-dimension lemma (Lemma 4.3), the definition of g, and the small mean-dimension bound of Y_g (Steps 2–6 align with the text) . However, Step 7 of the candidate solution incorrectly concludes that equality of outputs along all times forces ε-closeness on every length-m orbit block for the constructed single factor; this misuses the Lemma 4.3 fiber-embedding (E_p) because the factor encodes only a coordinate of F, not the values of E_p on the fiber, and also overinterprets property (3) in Proposition 3.1 regarding where 0 sits relative to a tile’s interior. The paper does not claim such pointwise ε-diameter control; it only obtains a quantitative width-dimension bound and then takes a product over scales to deduce mdim(π,T)=0 .
Referee report (LaTeX)
\textbf{Recommendation:} minor revisions \textbf{Journal Tier:} specialist/solid \textbf{Justification:} The paper establishes a clean and technically sound construction of factors of arbitrarily small mean dimension with zero relative mean dimension for systems with the marker property. The method blends known tiling and width-dimension techniques with a sparse time-coding scheme in a natural way. While most ingredients are standard, the synthesis and the relative dimension analysis are meaningful and well executed. Minor clarifications would improve readability, but the work appears correct and suitable for publication.