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2506.13167

Quenched invariance principle with a rate for random dynamical systems

Zhenxin Liu, Benoit Saussol, Sandro Vaienti, Zhe Wang

correcthigh confidence
Category
Not specified
Journal tier
Strong Field
Processed
Sep 28, 2025, 12:56 AM

Audit review

The paper’s Theorem 3.2 states the self-normalized quenched invariance principle with Wasserstein rate W_{q/4}(W^ω_n, B) ≤ C n^{-1/4 + 1/(2q)} under (P1)–(P8) for a > 5 and q ≥ 4, with W^ω_n defined via the variance-profile time change N^ω_n(t) built from Σ_n^2(ω) as in equations (3.1)–(3.2) . The proof uses two martingale–coboundary decompositions: a primary decomposition ϕ = ψ + χ∘F − χ with ψ a reverse martingale difference (Lemma 4.1) and a secondary decomposition for ϕ̆ controlling sums of squares to compare the predictable quadratic variation with the deterministic profile, enabling the Skorokhod-embedding/time-change analysis (Sections 4–6) . By contrast, the model’s solution incorrectly asserts Σ_n^2(ω) = ∫(S_n^g)^2 dµ_ω + O(1) and uses E(V_k) = Σ_k^2(ω) for the martingale array built from g; the paper proves that Σ_n^2(ω)−η_n^2(ω) is in fact O_ω(n^{1/2} + n^{1/q}), not O(1) (Lemma 6.1) and carefully bridges the normalization/indexing mismatch via the secondary decomposition and maximal bounds . Without these ingredients, the model’s claimed n^{-1/2} coboundary reduction and its time-change control are not justified. The paper’s approach is internally consistent and aligns with the known n^{-1/4} barrier for Skorokhod embeddings (Remark 3.3) .

Referee report (LaTeX)

\textbf{Recommendation:} minor revisions

\textbf{Journal Tier:} strong field

\textbf{Justification:}

The manuscript rigorously establishes a quenched Wasserstein invariance principle with quantitative rates for random Young towers, introducing a secondary martingale–coboundary decomposition to control quadratic-variation errors. The results are timely and technically solid, with clear connections to the martingale-embedding literature and random dynamical systems. While the exposition is dense in places, the arguments appear correct and the contributions are significant for specialists in ergodic theory and probabilistic limit theorems for dynamical systems.