English

On varieties whose general surface section has negative Kodaira dimension

Algebraic Geometry 2023-12-19 v2

Abstract

In this paper, inspired by work of Fano, Morin and Campana--Flenner, we give a full projective classification of (however singular) varieties of dimension 3 whose general hyperplane sections have negative Kodaira dimension, and we partly extend such a classification to varieties of dimension n4n\geq 4 whose general surface sections have negative Kodaira dimension. In particular we prove that a variety of dimension n3n\geq 3 whose general surface sections have negative Kodaira dimension is birationally equivalent to the product of a general surface section times \pn2\p^{n-2} unless (possibly) if the variety is a cubic hypersurface.

Keywords

Cite

@article{arxiv.2305.08730,
  title  = {On varieties whose general surface section has negative Kodaira dimension},
  author = {Ciro Ciliberto and Claudio Fontanari},
  journal= {arXiv preprint arXiv:2305.08730},
  year   = {2023}
}
R2 v1 2026-06-28T10:34:51.838Z