A Symmetry Method for Key Vanishing Lemmas and Optimal $2$-Jet Thresholds for Hyperbolicity

This manuscript reports on an ongoing project. We develop a new symmetry-based method for establishing vanishing results for negatively twisted invariant 2-jet differentials, both on generic surfaces in ${\mathbb{P}}^3$ and on complements of generic plane curves. The approach improves upon the recent work of Hou–Huynh–Merker–Xie by using a two-term perturbation of Fermat-type equations that is invariant under an involution exchanging two coordinates. The induced linear action on the space of invariant 2-jet differentials, combined with an elementary eigenvector argument from the representation theory of $\mathbb{Z}\mathrm{/}2\mathbb{Z}$, generates numerous additional linear constraints. This transforms the previously intractable systems into highly overdetermined ones, which we solve with a C++ implementation incorporating parallelization and modular arithmetic. Our ultimate goal is to prove that a very generic surface in ${\mathbb{P}}^3$ of degree $d⩾15$ is Kobayashi hyperbolic, and that the complement of a generic curve in ${\mathbb{P}}^2$ of degree $d⩾11$ is hyperbolic. As a concrete step, we prove here that a very generic surface in ${\mathbb{P}}^3$ of degree $d⩾16$ is Kobayashi hyperbolic. The method developed in this paper also lays the theoretical foundation for the vanishing results needed to reach the optimal bounds. Since many colleagues have asked to see the new symmetry method, we are making this manuscript available now. The C++ code for the remaining cases $d=15$ and $d=11$ is already written and the computations are underway; we expect to complete them in the near future.