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2408.08854

A dichotomy for the Hofer growth of area preserving maps on the sphere via symmetrization

Lev Buhovsky, Ben Feuerstein, Leonid Polterovich, Egor Shelukhin

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

Audit review

The uploaded paper proves the enhanced dichotomy on S^2 via the symmetrization map Σ, including the uniform constant 19·Area(S^2), through a bounded-conjugation estimate to a one-parameter subgroup in the Hofer completion of the even-height subgroup (Theorem 1.3) and a direct enhanced dichotomy statement (Theorem 3.1) . The candidate solution follows the same strategy: it invokes this symmetrization, the bounded-conjugation error, and the growth dichotomy to conclude either linear Hofer growth or a uniform Hofer bound. The only issue is a minor metric-notation slip (using d where the paper uses the completion d̂ in intermediate steps); the conclusion still follows because d̂ restricts to d on Ham(S^2) and the bound is applied when Σ(H)=0, yielding d(1,φ^t_H)=d̂(1,φ^t_H) ≤ 19·Area(S^2) for all t .

Referee report (LaTeX)

\textbf{Recommendation:} minor revisions

\textbf{Journal Tier:} strong field

\textbf{Justification:}

The manuscript establishes an enhanced dichotomy for autonomous Hamiltonian flows on S\^2 with an explicit universal constant using a newly developed symmetrization technique. The argument is technically sophisticated and blends symplectic geometric constructions with quantitative Floer-theoretic tools. The result is important and the approach appears robust, with clear prospects for generalizations. Minor exposition refinements would improve accessibility.