English

Sextic double solids with Artin-Mumford obstructions to rationality

Algebraic Geometry 2019-09-16 v2

Abstract

We study a double solid X branched along a nodal sextic surface in a projective space and the 2-torsion subgroup in the third integer cohomology group of a resolution of singularities of X. This group can be considered as an obstruction to rationality of X. Studying this group we conclude that all sextic double solids admitting non-trivial obstructions to rationality are branched along determinantal surfaces of very specific type and we provide an explicit list of them.

Keywords

Cite

@article{arxiv.1901.05055,
  title  = {Sextic double solids with Artin-Mumford obstructions to rationality},
  author = {Alexandra Kuznetsova},
  journal= {arXiv preprint arXiv:1901.05055},
  year   = {2019}
}

Comments

22 pages; v2: exposition improved, some typos corrected