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2107.02663

Bifurcation Loci of Families of Finite Type Meromorphic Maps

Matthieu Astorg, Anna Miriam Benini, Núria Fagella

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

Audit review

The paper proves the Accessibility Theorem (Theorem 4.4) rigorously: it normalizes a tract via Φλ, constructs a parameter curve λ(t) by a shooting argument G(λ(t)) = Φ−1_{λ0}(−t), and then builds forward-invariant domains U_t so that f^{n+1}_{λ(t)} maps U_t compactly into itself; Koebe and quasiconformal distortion estimates together with condition (T) imply the multiplier tends to 0 as the cycle exits the domain . In contrast, the model’s proof hinges on an unsubstantiated Weierstrass-preparation/implicit-function step in (λ,w) to solve f^n_λ(v_λ+e^w)=g_λ(w), despite g_λ not being shown to depend holomorphically on λ and without any actual pole in λ at λ0; it also assumes boundedness of derivative factors on a compact set without establishing the required uniform geometric control. These gaps contradict the paper’s careful use of the shooting lemma and invariant-domain method, which avoid precisely these pitfalls. The paper’s condition (T) and its consequences are correctly stated and used (Definition 4.1 and Lemma 4.3) .

Referee report (LaTeX)

\textbf{Recommendation:} minor revisions

\textbf{Journal Tier:} strong field

\textbf{Justification:}

The Accessibility Theorem is established cleanly in a very general setting for natural families of finite type meromorphic maps. The proof is conceptually strong and technically careful, combining a new shooting lemma with classical distortion tools to control multipliers. The results substantially extend the understanding of virtual centers and bifurcation phenomena beyond the rational and entire settings. Some minor expository amplifications would further improve accessibility, but the core mathematics appears correct and impactful.