2507.05027
Growth of generalized greatest common divisors along orbits of self-rational maps on projective varieties
Yohsuke Matsuzawa
correctmedium confidence
- Category
- Not specified
- Journal tier
- Specialist/Solid
- Processed
- Sep 28, 2025, 12:56 AM
- arXiv Links
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Audit review
The paper proves the limit using a refined r-jet/linear-system method on the blow-up and the iteratively finite locus, culminating in a uniform bound for h_{f^{-n}(Y)} relative to h_H and a block-growth inequality for h_H along the orbit. The candidate solution hinges on an unsubstantiated uniform inequality h_Z(P) ≲ deg_H(Z)^{1/c} h_H(P) derived from a naive Hilbert-polynomial count and Bertini; the paper explicitly notes that such a clean general upper bound for subscheme heights is not known and is highly nontrivial for positive-dimensional Y. The model also blurs scheme-theoretic inverse images f^{-n}(Y) (used in functoriality) with numerical cycle pullbacks (f^n)^*Y, and assumes degree growth control that the paper carefully avoids.
Referee report (LaTeX)
\textbf{Recommendation:} minor revisions \textbf{Journal Tier:} specialist/solid \textbf{Justification:} The paper establishes an unconditional criterion showing that generalized gcd heights along orbits are negligible compared to an ample height under a natural dynamical-degree vs. arithmetic-degree gap. The proof is technically careful, leveraging blow-ups, thickenings, and a block-growth inequality for generic orbits. The result is of interest to specialists in arithmetic dynamics and Diophantine geometry. Minor clarifications to guide the reader through the interplay of the iteratively finite locus and the height bounds would further strengthen the exposition.