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2406.16604

Volume of Algebraically Integrable Foliations and Locally Stable Families

Jingjun Han, Junpeng Jiao, Mengchu Li, Jihao Liu

correcthigh confidenceCounterexample detected
Category
Not specified
Journal tier
Strong Field
Processed
Sep 28, 2025, 12:56 AM

Audit review

The paper proves that for any lc algebraically integrable foliated triple (X, F, B) of fixed rank d, with coefficients in a DCC set Γ and fixed leaf volume v, there exists a uniform positive lower bound δ for vol(KF+B) when KF+B is big, and moreover the possible volumes lie in a discrete set depending only on d, Γ, v (Theorem 1.5). Their proof reduces, via ACSS/core modifications and finite covers, to a stable family and shows vol(KF+B) = l·vol(KXT/T+BT), where dim XT is uniformly bounded in terms of d, Γ, v, whence discreteness and a uniform lower bound follow. The candidate’s product construction ignores this moduli-theoretic reduction. In particular, their isotrivial product with a horizontal boundary cannot survive the reduction to a (generically finite) moduli image without violating Lemma 2.19 (which forbids bigness for stable families not of maximal variation). Further, the candidate mis-normalizes volume (vol(D)=D^n, not D^n/n!) and omits the binomial factor in the product self-intersection; although these errors do not salvage their conclusion numerically, the decisive issue is that, after the paper’s reduction steps, vol(KF+B) is controlled by intersection numbers on a space of bounded dimension with bounded indices, so it cannot tend to 0 nor accumulate in the manner proposed. Thus the paper’s statements (1) and (2) stand, and the model’s counterexamples fail.

Referee report (LaTeX)

\textbf{Recommendation:} no revision

\textbf{Journal Tier:} strong field

\textbf{Justification:}

The paper establishes sharp discreteness and lower-bound results for volumes of lc algebraically integrable foliations under fixed leaf volume, via a robust moduli-theoretic reduction (ACSS/core modifications, finite covers, stabilization, and intersection-number control on bounded-dimensional spaces). The candidate’s counterexamples collapse under this reduction, and the results directly address questions of Cascini–Hacon–Langer.