Vojta's abc conjecture for entire curves in toric varieties highly ramified over the boundary
Min Ru, Julie Tzu-Yueh Wang
TL;DR
This work proves a Vojta-ABC type inequality for entire curves in ${\mathbb P}^n(\mathbb C)$ under the hypothesis of high ramification along the coordinate hyperplanes, and extends the framework to projective toric varieties to obtain Campana orbifold conclusions for finite coverings. The authors develop a parabolic Nevanlinna theory, including Jensen's formula, logarithmic derivative, and a moving gcd theorem, and then establish an abc theorem on parabolic Riemann surfaces. The main theorem is proved by translating to a parabolic setting, applying gcd- and proximity-type bounds to holomorphic curves represented by units on parabolic open Riemann surfaces, and combining these with a parabolic abc inequality to yield truncation-level results with effective exceptional sets. The toric extension leverages affine covers and Campana orbifold formalism to deduce orbifold-structure hyperbolicity-type consequences for finite covers, culminating in a Campana orbifold conjecture for toric-geometric settings. Overall, the paper provides a rigorous analytic-geometry pipeline from parabolic Nevanlinna theory to abc-type results and toric/campana consequences with explicit, computable data.
Abstract
We prove Vojta's abc conjecture for projective space ${\Bbb P}^n({\Bbb C})$, assuming that the entire curves in ${\Bbb P}^n({\Bbb C})$ are highly ramified over the coordinate hyperplanes. This extends the results of Guo Ji and the second-named author for the case $n=2$ (see \cite{GW22}). We also explore the corresponding results for projective toric varieties. Consequently, we establish a version of Campana's orbifold conjecture for finite coverings of projective toric varieties.
