English

Demailly's notion of algebraic hyperbolicity: geometricity, boundedness, moduli of maps

Algebraic Geometry 2021-09-24 v3 Differential Geometry

Abstract

Demailly's conjecture, which is a consequence of the Green-Griffiths-Lang conjecture on varieties of general type, states that an algebraically hyperbolic complex projective variety is Kobayashi hyperbolic. Our aim is to provide evidence for Demailly's conjecture by verifying several predictions it makes. We first define what an algebraically hyperbolic projective variety is, extending Demailly's definition to (not necessarily smooth) projective varieties over an arbitrary algebraically closed field of characteristic zero, and we prove that this property is stable under extensions of algebraically closed fields. Furthermore, we show that the set of (not necessarily surjective) morphisms from a projective variety YY to a projective algebraically hyperbolic variety XX that map a fixed closed subvariety of YY onto a fixed closed subvariety of XX is finite. As an application, we obtain that Aut(X)(X) is finite and that every surjective endomorphism of XX is an automorphism. Finally, we explore "weaker" notions of hyperbolicity related to boundedness of moduli spaces of maps, and verify similar predictions made by the Green-Griffiths-Lang conjecture on hyperbolic projective varieties.

Keywords

Cite

@article{arxiv.1807.03665,
  title  = {Demailly's notion of algebraic hyperbolicity: geometricity, boundedness, moduli of maps},
  author = {Ariyan Javanpeykar and Ljudmila Kamenova},
  journal= {arXiv preprint arXiv:1807.03665},
  year   = {2021}
}

Comments

27 pages. Included new result (Theorem 1.14). No other significant changes