English

(Stable) rationality is not deformation invariant

Algebraic Geometry 2015-12-23 v4

Abstract

We prove the existence of a family XB\mathcal{X}\rightarrow B of smooth projective fourfolds, such that the very general fiber Xt\mathcal{X}_t is not stably rational (a fortiori not rational), but some special fibers Xt\mathcal{X}_t are rational (a fortiori stably rational).

Keywords

Cite

@article{arxiv.1511.03591,
  title  = {(Stable) rationality is not deformation invariant},
  author = {Claire Voisin},
  journal= {arXiv preprint arXiv:1511.03591},
  year   = {2015}
}

Comments

The paper is withdrawn by the author, who has been informed by A. Beauville that his paper arXiv:1411.3122, on which the present paper heavily depends, has a serious gap

R2 v1 2026-06-22T11:42:47.390Z