English

Rationally connected rational double covers of primitive Fano varieties

Algebraic Geometry 2024-04-17 v3

Abstract

We show that for a Zariski general hypersurface VV of degree M+1M+1 in PM+1{\mathbb P}^{M+1} for M5M\geqslant 5 there are no Galois rational covers XVX\dashrightarrow V of degree d2d\geqslant 2 with an abelian Galois group, where XX is a rationally connected variety. In particular, there are no rational maps XVX\dashrightarrow V of degree 2 with XX rationally connected. This fact is true for many other families of primitive Fano varieties as well and motivates a conjecture on absolute rigidity of primitive Fano varieties.

Keywords

Cite

@article{arxiv.1910.08975,
  title  = {Rationally connected rational double covers of primitive Fano varieties},
  author = {Aleksandr V. Pukhlikov},
  journal= {arXiv preprint arXiv:1910.08975},
  year   = {2024}
}

Comments

the final journal version