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.
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