Hyperbolicity of Fermat-type curves and their complements
Anh Tuan Nguyen
TL;DR
The paper addresses hyperbolicity of Fermat-type curves and their complements in $CP^2$ by transporting generalized Borel theorems into the CP$^2$ setting via Nevanlinna theory. Using a refined CP$^2$-specific four-case degeneracy framework (Cartan SMT and truncated counting), it proves hyperbolicity for the complement of Noguchi-El Goul's curves when $d>8$ and for Noguchi-Shirosaki's Fermat-type curves under explicit parameter ranges. These results improve previous degree bounds and, as a by-product, strengthen Lang-Vojta conjecture bounds for families of hyperbolic hypersurfaces. The work provides new low-degree hyperbolic examples and sharpens the interaction between Nevanlinna theory and complex hyperbolicity in dimension two.
Abstract
In this paper, by using the generalized Borel theorems in $\mathbb{CP}^2$, we show the hyperbolicity of Fermat type curves and their complement in $\mathbb{CP}^2$. This improves Noguchi-Shirosaki's and Demailly-El Goul's degree bounds.
