English

Some Calabi-Yau threefolds with obstructed deformations over the Witt vectors

Algebraic Geometry 2007-05-23 v2

Abstract

I construct some smooth Calabi-Yau threefolds in characteristic two and three that do not lift to characteristic zero. These threefolds are pencils of supersingular K3-surfaces. The construction depends on Moret-Bailly's pencil of abelian surfaces and Katsura's analysis of generalized Kummer surfaces. The threefold in characteristic two turns out to be nonrigid.

Keywords

Cite

@article{arxiv.math/0302064,
  title  = {Some Calabi-Yau threefolds with obstructed deformations over the Witt vectors},
  author = {Stefan Schroeer},
  journal= {arXiv preprint arXiv:math/0302064},
  year   = {2007}
}

Comments

16 pages, some proofs simplified, discriminants in Theorem 6.4 corrected