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2108.13519

Infinite Compositions and Complex Dynamics; Generalizing Schröder and Abel Functions

James David Nixon

incompletehigh confidence
Category
math.DS
Journal tier
Note/Short/Other
Processed
Sep 28, 2025, 12:56 AM

Audit review

The paper’s Theorem 4.1 aims to construct an inverse Schröder function under assumptions (1)–(3) via an iterative correction vn and a Banach fixed point argument, but the key contraction step is not justified: the sup-norm estimate that introduces a factor q<1 from the rescaling w↦λw is asserted without conditions ensuring strict contraction, and the O(w)-asymptotic near w=0 is invoked without a complete derivation from earlier results that are stated for a different scaling regime. The model’s solution gives a cleaner plan (Denjoy–Wolff/Koenigs coordinate + logarithmic covering), but it silently assumes the existence of a simply connected, forward-invariant ‘tail’ A∞ on which a univalent Fatou–Abel coordinate exists; this is plausible under the hypotheses yet not proved in the write-up. Hence both proofs have important gaps.

Referee report (LaTeX)

\textbf{Recommendation:} major revisions

\textbf{Journal Tier:} note/short/other

\textbf{Justification:}

The topic is interesting and the approach via infinite compositions is creative. However, the main existence theorem’s proof contains a critical, unproven contraction estimate and an undeveloped asymptotic passage. The result may still be true under the stated hypotheses, but substantial revisions are needed to supply rigorous estimates and clarify domains and norms. As written, the paper should not be accepted without these corrections.