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2409.07636

Sturmian external angles of primitive components in the Mandelbrot set

Benjamín A. Itzá-Ortiz, Mónica Moreno Rocha, Víctor Nopal-Coello

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

Audit review

The paper’s Theorem A states precisely that for n ≥ 1 and rationals P/Q, a/b satisfying the 01-Hyp, the angle θ = θ01(P/Q, a/b, n) is periodic of exact period b and the parameter ray Rθ lands at the root of a primitive hyperbolic component of period b; the proof proceeds via an explicit computation of the conjugate angle and an analysis of kneading sequences, invoking Cor. 5.5 of [LS94] to conclude primitivity . The candidate solution reaches the same conclusion by a different route (global ray-landing/wake theory and orbit-portrait arguments). Aside from a minor conflation of dynamic vs parameter rays and a likely misstatement about ray-periods in the satellite case (the paper explicitly notes that the characteristic angles of a component of period m are m-periodic under doubling) , the model’s reasoning aligns with the paper’s outcome. The core ingredients used by the paper (broken-line construction, 01-Hyp, periodicity and minimal period b of θ01(P/Q,a/b,n)) are clearly stated and justified .

Referee report (LaTeX)

\textbf{Recommendation:} minor revisions

\textbf{Journal Tier:} specialist/solid

\textbf{Justification:}

This work offers a concrete, implementable algorithm to compute periodic Sturmian angles and pin down the corresponding primitive components in the Mandelbrot set. Its conceptual bridge between cutting/mechanical sequences and parameter-plane structure is well-executed and correct. The main theorems are proved carefully, with constructive details. Minor improvements in exposition, especially clarifying dynamic vs parameter ray language and centralising certain case analyses, would further enhance readability.