English

Projective varieties with nef tangent bundle in positive characteristic

Algebraic Geometry 2020-12-18 v1

Abstract

Let XX be a smooth projective variety defined over an algebraically closed field of positive characteristic pp whose tangent bundle is nef. We prove that XX admits a smooth morphism XMX \to M such that the fibers are Fano varieties with nef tangent bundle and TMT_M is numerically flat. We also prove that extremal contractions exist as smooth morphisms. As an application, we prove that, if the Frobenius morphism can be lifted modulo p2p^2, then XX admits, up to a finite \'etale Galois cover, a smooth morphism onto an ordinary abelian variety whose fibers are products of projective spaces.

Keywords

Cite

@article{arxiv.2012.09419,
  title  = {Projective varieties with nef tangent bundle in positive characteristic},
  author = {Akihiro Kanemitsu and Kiwamu Watanabe},
  journal= {arXiv preprint arXiv:2012.09419},
  year   = {2020}
}

Comments

24 pages

R2 v1 2026-06-23T21:02:24.328Z