Back to search
2411.13624

A PRIORI BOUNDS FOR HÉNON-LIKE RENORMALIZATION

Sylvain Crovisier, Mikhail Lyubich, Enrique Pujals, Jonguk Yang

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

Audit review

The paper proves uniform bounded distortion for Hénon-like renormalizations by reducing the 2D dynamics to a controlled 1D mapping scheme via vertical projections near a dynamical critical value and then applying 1D cross-ratio/Koebe distortion estimates; the argument carefully uses regularity and bounded-type combinatorics to ensure disjointness and uniform length bounds. The candidate solution attempts a direct “hyperbolic sum-of-variations” estimate along horizontal leaves, but it incorrectly assumes that F maps genuine horizontal leaves to horizontal leaves and that forward iterates of two points on a horizontal arc remain on a common horizontal leaf. This invalidates the key pullback-length estimate and the geometric-series bound that follows. The paper’s strategy does not suffer from these issues and appears internally consistent with its stated hypotheses.

Referee report (LaTeX)

\textbf{Recommendation:} no revision

\textbf{Journal Tier:} strong field

\textbf{Justification:}

The paper delivers a robust proof of a priori bounds for Hénon-like renormalization by leveraging a sophisticated projection-based reduction to a 1D mapping scheme and then deploying classical 1D distortion control. It addresses subtle 2D issues that defeat naive bounded-distortion arguments. The structure, from regularity hypotheses to the construction of the mapping scheme and the application of Koebe/cross-ratio distortion, is coherent and well justified.