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2405.17173

ITERATION PROBLEM FOR SEVERAL CHAOS IN NON-AUTONOMOUS DISCRETE SYSTEM

Hongbo Zeng, Chuangxia Huang, Bingwen Liu

incompletemedium confidence
Category
Not specified
Journal tier
Specialist/Solid
Processed
Sep 28, 2025, 12:56 AM

Audit review

The paper asserts that Li–Yorke chaos is preserved under k-iterates provided the non-autonomous system f1,∞ merely converges to a map f (Theorem 1), but in the necessity proof it implicitly uses stability of finite compositions under pointwise convergence, specifically the step claiming lim_i f^ℓ_{kq_i+r+1}(x0) = f^ℓ(x0) without uniform convergence or an equicontinuity/N-convergence hypothesis, leaving a material gap in the argument (see the proof of Theorem 1 and the step following (3.1)–(3.2)) . The paper correctly defines the k-th iterate as the block system f[k]1,∞ := (f^k_{k(n−1)+1})n≥1 and contrasts it with uniform-convergence-based lemmas . By contrast, the model conflates the block iterate f[k]1,∞ with the sliding-window sequence (g_n = f^k_n), incorrectly claiming they have identical n-th iterates, and then appeals to a broad iterate-invariance theorem without the extra hypotheses (e.g., equicontinuity or N-convergence) that the paper itself points to as typically needed for such invariance results for related chaos notions . Consequently, both the paper’s proof (as written) and the model’s solution are incomplete.

Referee report (LaTeX)

\textbf{Recommendation:} major revisions

\textbf{Journal Tier:} specialist/solid

\textbf{Justification:}

The manuscript addresses iteration invariance for several chaos notions in non-autonomous discrete systems, aiming to relax uniform convergence assumptions known from prior work. The main Li–Yorke result would be a meaningful strengthening, but the necessity proof relies on passing limits through finite compositions under merely pointwise convergence, a step that is nontrivial and presently unjustified. Other results (DC2' under uniform convergence, Kato's chaos under finite generation/uniform convergence) are on firmer ground, and the DC3 counterexample is useful. Substantial revision is needed to fix Theorem 1 (either by adding appropriate hypotheses such as equicontinuity or N-convergence, or by providing a rigorous new argument).