2209.06594
Orbits Closeness for Slowly Mixing Dynamical Systems
Jérôme Rousseau, Mike Todd
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 a general upper bound (Theorem 1.1) and then, under an inducing scheme satisfying (1.1) with C_{μ_F}=C_μ, upgrades this to a full limit 2/C_μ (Theorem 2.1) via a clean subsequence/ergodic-time-change argument; see the statement and proof excerpts for Theorem 1.1 and Theorem 2.1 in the uploaded PDF . By contrast, the model’s Step 1 contains a summability error: choosing r_n = n^{-(2/C_μ+ε)} and then using I_μ(r) ≤ r^{C_μ−ε} does not in general make ∑_k 2^{2k}(r_{2^k})^{C_μ−ε} summable unless an extra margin (e.g., δ>0 or a log factor) is introduced. This undermines the claimed universal upper bound proof. The model’s Step 2 also misstates a shift inequality (it uses the same n, whereas one needs to adjust n by a finite amount). The remaining steps align in spirit with the paper (inducing and time-change), but the two noted issues are substantive enough that the model’s proof, as written, is not correct, while the paper’s argument is correct.
Referee report (LaTeX)
\textbf{Recommendation:} no revision \textbf{Journal Tier:} specialist/solid \textbf{Justification:} The paper cleanly extends orbit-closeness scaling laws to slowly mixing systems by inducing, without requiring mixing assumptions, and also treats flows and counterexamples. The arguments are standard but executed carefully, with clear hypotheses (existence of C\_μ and projection of μ\_F) and succinct proofs. The contribution is solid and useful to specialists.