Rationally connected rational double covers of primitive Fano varieties

We show that for a Zariski general hypersurface $V$ of degree $M+1$ in ${\mathbb P}^{M+1}$ for $M\geqslant 5$ there are no Galois rational covers $X\dashrightarrow V$ of degree $d\geqslant 2$ with an abelian Galois group, where $X$ is a rationally connected variety. In particular, there are no ratio...

Full description

Bibliographic Details
Main Author: Aleksandr V. Pukhlikov
Format: Article
Language:English
Published: Association Epiga 2020-11-01
Series:Épijournal de Géométrie Algébrique
Subjects:
Online Access:https://epiga.episciences.org/5890/pdf
_version_ 1798029637592285184
author Aleksandr V. Pukhlikov
author_facet Aleksandr V. Pukhlikov
author_sort Aleksandr V. Pukhlikov
collection DOAJ
description We show that for a Zariski general hypersurface $V$ of degree $M+1$ in ${\mathbb P}^{M+1}$ for $M\geqslant 5$ there are no Galois rational covers $X\dashrightarrow V$ of degree $d\geqslant 2$ with an abelian Galois group, where $X$ is a rationally connected variety. In particular, there are no rational maps $X\dashrightarrow V$ of degree 2 with $X$ 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.
first_indexed 2024-04-11T19:28:29Z
format Article
id doaj.art-50deb7bbaf324680823f3b3c6a813ad6
institution Directory Open Access Journal
issn 2491-6765
language English
last_indexed 2024-04-11T19:28:29Z
publishDate 2020-11-01
publisher Association Epiga
record_format Article
series Épijournal de Géométrie Algébrique
spelling doaj.art-50deb7bbaf324680823f3b3c6a813ad62022-12-22T04:07:04ZengAssociation EpigaÉpijournal de Géométrie Algébrique2491-67652020-11-01Volume 410.46298/epiga.2020.volume4.58905890Rationally connected rational double covers of primitive Fano varietiesAleksandr V. PukhlikovWe show that for a Zariski general hypersurface $V$ of degree $M+1$ in ${\mathbb P}^{M+1}$ for $M\geqslant 5$ there are no Galois rational covers $X\dashrightarrow V$ of degree $d\geqslant 2$ with an abelian Galois group, where $X$ is a rationally connected variety. In particular, there are no rational maps $X\dashrightarrow V$ of degree 2 with $X$ 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.https://epiga.episciences.org/5890/pdfmathematics - algebraic geometry14e05, 14e07
spellingShingle Aleksandr V. Pukhlikov
Rationally connected rational double covers of primitive Fano varieties
Épijournal de Géométrie Algébrique
mathematics - algebraic geometry
14e05, 14e07
title Rationally connected rational double covers of primitive Fano varieties
title_full Rationally connected rational double covers of primitive Fano varieties
title_fullStr Rationally connected rational double covers of primitive Fano varieties
title_full_unstemmed Rationally connected rational double covers of primitive Fano varieties
title_short Rationally connected rational double covers of primitive Fano varieties
title_sort rationally connected rational double covers of primitive fano varieties
topic mathematics - algebraic geometry
14e05, 14e07
url https://epiga.episciences.org/5890/pdf
work_keys_str_mv AT aleksandrvpukhlikov rationallyconnectedrationaldoublecoversofprimitivefanovarieties