English

Derived symmetries for crepant contractions to hypersurfaces

Algebraic Geometry 2026-01-28 v4

Abstract

Given a crepant contraction f to a singularity X, we may expect a derived symmetry of the source of f. Under easily-checked geometric assumptions, I construct such a symmetry when X is a hypersurface in a smooth ambient S, using a spherical functor from the derived category of S. I describe this symmetry, relate it to other symmetries, and establish its compatibility with base change.

Keywords

Cite

@article{arxiv.2409.19555,
  title  = {Derived symmetries for crepant contractions to hypersurfaces},
  author = {W. Donovan},
  journal= {arXiv preprint arXiv:2409.19555},
  year   = {2026}
}

Comments

Streamlined exposition. 35 pages, 3 figures