English

Nef anti-canonical divisors and rationally connected fibrations

Algebraic Geometry 2019-07-10 v2

Abstract

We study the Iitaka-Kodaira dimension of nef relative anti-canonical divisors. As a consequence, we prove that given a complex projective variety with klt singularities, if the anti-canonical divisor is nef, then the dimension of a general fibre of the maximal rationally connected fibration is at least the Iitaka-Kodaira dimension of the anti-canonical divisor.

Keywords

Cite

@article{arxiv.1802.03732,
  title  = {Nef anti-canonical divisors and rationally connected fibrations},
  author = {Sho Ejiri and Yoshinori Gongyo},
  journal= {arXiv preprint arXiv:1802.03732},
  year   = {2019}
}

Comments

13 pages, v2: an error in Theorem 3.1 corrected