English

Hilbert schemes of points on canonical surfaces

Algebraic Geometry 2026-07-09 v1 Representation Theory

Abstract

For n1n\geq 1, we investigate the Hilbert scheme of nn-points on a surface SS with canonical singularities. We generalise the well-known theorem of Fogarty by showing that the underlying reduced subscheme of Hilbn(S)\operatorname{Hilb}^n(S) is a normal variety of dimension 2n2n with canonical singularities, and for n7n\leq 7, we show that Hilbn(S)\operatorname{Hilb}^n(S) is reduced. When SS has symplectic singularities over C\mathbb{C}, we show that the underlying reduced subscheme of Hilbn(S)\operatorname{Hilb}^n(S) also has symplectic singularities, thereby generalising a result of Beauville. Our results build on work of the first author with Gyenge, Gammelgaard and Szendr\H{o}i that sought to identify the underlying reduced subscheme of the Hilbert scheme of nn-points on a Kleinian singularity with a Nakajima quiver variety.

Keywords

Cite

@article{arxiv.2607.08913,
  title  = {Hilbert schemes of points on canonical surfaces},
  author = {Alastair Craw and Ryo Yamagishi},
  journal= {arXiv preprint arXiv:2607.08913},
  year   = {2026}
}

Comments

33 pages. This paper contains the geometric results from v1 of our arXiv:2312.08527 preprint, though we establish reducedness only for n\leq 7