English

Flips for spaces of quadrics on del Pezzo varieties

Algebraic Geometry 2026-03-02 v2

Abstract

For a cubic hypersurface XX, work of Galkin--Shinder and Voisin shows the existence of a birational map relating the Hilbert scheme of two points X[2]X^{[2]} with a certain projective bundle over XX. Belmans--Fu--Raedschelders show that this is a standard flip, a particularly nice type of birational map inducing decompositions of derived categories. We show that this geometric construction extends to produce standard flips for Hilbert schemes of quadrics on various higher-dimensional del Pezzo varieties of degree at least 3, including cubics, intersections of two quadrics, and linear sections of Gr(2,5)\mathrm{Gr}(2, 5). The resulting construction also generalizes results of Chung--Hong--Lee for quintic del Pezzo varieties. As an application, we produce a conjectural semiorthogonal decompositions for orthogonal Grassmannians of lines.

Keywords

Cite

@article{arxiv.2602.07366,
  title  = {Flips for spaces of quadrics on del Pezzo varieties},
  author = {Saket Shah},
  journal= {arXiv preprint arXiv:2602.07366},
  year   = {2026}
}

Comments

Minor revisions and typo corrections