English

Kernels for Grassmann Flops

Algebraic Geometry 2021-04-28 v2

Abstract

We develop a generalization of the QQ-construction of the first author, Diemer, and the third author for Grassmann flips. This generalization provides a canonical idempotent kernel on the derived category of the associated global quotient stack. The idempotent kernel, after restriction, induces a semi-orthogonal decomposition which compares the flipped varieties. Furthermore its image, after restriction to the geometric invariant theory semistable locus, "opens" a canonical "window" in the derived category of the quotient stack. We check this window coincides with the set of representations used by Kapranov to form a full exceptional collection on Grassmannians.

Keywords

Cite

@article{arxiv.1904.12195,
  title  = {Kernels for Grassmann Flops},
  author = {Matthew R. Ballard and Nitin K. Chidambaram and David Favero and Patrick K. McFaddin and Robert R. Vandermolen},
  journal= {arXiv preprint arXiv:1904.12195},
  year   = {2021}
}

Comments

30 pages, expanded to identify the orthogonal for Grassmann flips, accepted for publication by Journal de Math\'ematiques Pures et Appliqu\'ees

R2 v1 2026-06-23T08:51:15.868Z