English

Twisted cotangent sheaves and a Kobayashi-Ochiai theorem for foliations

Algebraic Geometry 2017-10-26 v2

Abstract

Let X be a normal projective variety, and let A be an ample Cartier divisor on X. We prove that the twisted cotangent sheaf ΩXA\Omega_X \otimes A is generically nef with respect to the polarisation A unless X is a projective space. As an application we prove a Kobayashi-Ochiai theorem for foliations: if FTXF \subsetneq T_X is a foliation of rank r such that detFiFAdet F \equiv i_F A, then we have iFri_F \leq r.

Keywords

Cite

@article{arxiv.1307.3449,
  title  = {Twisted cotangent sheaves and a Kobayashi-Ochiai theorem for foliations},
  author = {Andreas Höring},
  journal= {arXiv preprint arXiv:1307.3449},
  year   = {2017}
}

Comments

13 pages, changed metadata