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2202.01007

CONVEXITY OF COMPLEMENTS OF LIMIT SETS FOR HOLOMORPHIC FOLIATIONS ON SURFACES

Bertrand Deroin, Christophe Dupont, Victor Kleptsyn

correcthigh confidence
Category
math.DS
Journal tier
Strong Field
Processed
Sep 28, 2025, 12:56 AM

Audit review

The paper proves that for a holomorphic foliation F on a compact Kähler surface satisfying (*), if the limit set L is thin (in particular if it has Lebesgue measure zero), then S\L is a modification of a Stein domain. It does so by constructing a Hermitian metric on the normal bundle with positive curvature near L (positivity along leaves, then near singularities, then in all directions on L using thinness), and then a proper strictly plurisubharmonic exhaustion on S\L, completing the argument via standard 1‑convex/Remmert reduction machinery. The candidate solution reproduces this strategy: uniqueness of a directed harmonic current (hence a well-defined limit set), potential-theoretic input from thinness to build transverse weights, positivity of the normal bundle near L, and a global psh exhaustion leading to 1‑convexity and modification of a Stein domain. Minor differences are cosmetic (e.g., emphasis on Lyapunov exponent negativity as an input rather than a byproduct, and referencing Brunella’s 2003 Inventiones paper rather than the specific Brunella result cited in the paper). Substantively, they match.

Referee report (LaTeX)

\textbf{Recommendation:} minor revisions

\textbf{Journal Tier:} strong field

\textbf{Justification:}

The result cleanly connects dynamical thinness of the limit set to complex-analytic convexity of its complement, handling singularities and fractal geometry through a careful curvature-building program. The argument is technically solid and extends classical insights. Minor expository improvements would further enhance accessibility.