English

Vanishing of Invariant 2-Jet Differentials and Improved Hyperbolicity Degree Bounds in Dimension Two

Complex Variables 2026-05-12 v2

Abstract

This paper establishes new degree bounds for Kobayashi hyperbolicity in dimension two. Our main results are: -- A very generic surface in P3\mathbb{P}^3 of degree at least 1717 is Kobayashi hyperbolic. -- The complement of a {\em generic} curve in P2\mathbb{P}^2 of degree at least 1212 is Kobayashi hyperbolic. These bounds improve the long-standing records in the field, lowering the threshold from 1818 to 1717 for surfaces (P\u{a}un) and from 1414 to 1212 for complements (Rousseau). Central to the proofs are new vanishing results for certain negatively twisted invariant 22-jet differentials, obtained through a novel combination of algebraic reduction and computer algebra. Since Demailly's Santa Cruz lectures in 1995, the thresholds for the existence of such differentials -- and consequently the limits of what 22-jet techniques can accomplish toward the Kobayashi conjecture in dimension two -- have been recognized as d=15d = 15 in the compact case and d=11d = 11 in the logarithmic case. While previous approaches were unable to reach these targets, the present work provides both the theoretical foundations and the algorithmic framework required to access them, and has already improved the known bounds to d=17d = 17 and d=12,13d = 12, 13, respectively. As an unexpected byproduct, our computational method reveals the existence of nonzero negatively twisted invariant 22-jet differentials with (m,t)=(3,1)(m,t) = (3,1) for hyperelliptic-type equations of degree at least 1111 in the logarithmic case and degree at least 1515 in the compact case, further illuminating the geometry of these special jet differentials.

Keywords

Cite

@article{arxiv.2603.14881,
  title  = {Vanishing of Invariant 2-Jet Differentials and Improved Hyperbolicity Degree Bounds in Dimension Two},
  author = {Lei Hou and Dinh Tuan Huynh and Joël Merker and Song-Yan Xie},
  journal= {arXiv preprint arXiv:2603.14881},
  year   = {2026}
}

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57 pages