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2112.02398

Metrics on Trees I. The Tower Algorithm for Interval Maps.

Giulio Tiozzo

wrongmedium confidence
Category
math.DS
Journal tier
Specialist/Solid
Processed
Sep 28, 2025, 12:56 AM

Audit review

The paper’s Theorem 4.1(1) asserts that for any ϕ ∈ BV the unnormalized sequence L^nϕ converges to an eigenvector of eigenvalue λ. This is incorrect for λ > 1, since ‖L^nϕ‖ typically grows like λ^n. The proof the paper gives actually uses normalization by Mn = ‖(f?)^n(m0)‖ and a spectral projector P (so L^nχJ/Mn → c·PχJ), which supports the correct normalized statement λ^{-n}L^nϕ → Pϕ. The model explicitly makes this normalization and otherwise reproduces the convergence of Hn, the semiconjugacy to a constant-slope map, and the uniform convergence fn → f∞ correctly. See Theorem 4.1 and its proof for the paper’s statement and use of Mn, and the spectral decomposition and high-entropy unimodal gap that underpin the argument (duality and setup; spectral decomposition; unimodal high-entropy spectral gap; iteration via mn and Hn; semiconjugacy via linearly expanded metrics; conditional convergence of gn, hn) .

Referee report (LaTeX)

\textbf{Recommendation:} minor revisions

\textbf{Journal Tier:} specialist/solid

\textbf{Justification:}

The paper makes a valuable, technically sound contribution tying Milnor’s tower algorithm to transfer-operator and kneading theory, securing convergence for unimodal maps with high entropy. The main correction needed is to state convergence of transfer iterates with the standard normalization; the proof already implements this. With that and a brief clarification on the existence of Hn, the work is solid and suitable for publication.