English

Virtual invariants from the non-associative Hilbert scheme

Algebraic Geometry 2025-12-23 v2

Abstract

We introduce a non-associative model for the Hilbert scheme of points in arbitrary dimension. We define a smooth ambient space, which we call the non-associative Hilbert scheme, containing the classical nested Hilbert scheme NHilbd(An)\mathrm{NHilb}^{\underline{d}}(\mathbb{A}^n) as the associativity, cut out by an explicit section of an associativity bundle. This construction yields canonical perfect obstruction theories and virtual fundamental classes on NHilbd(An)\mathrm{NHilb}^{\underline{d}}(\mathbb{A}^n) for all (n,d)(n,\underline d). Using virtual localization, we obtain closed formulas for these virtual classes as sums over admissible nested partitions. Over the punctual locus, we rewrite these as a single multivariable iterated residue formula governing all virtual integrals. Our construction works for all nn, produces positive-dimensional virtual classes when nn is large compared to the number of points, and we expect that they extend the non-commutative matrix model and virtual class construction on Calabi-Yau threefolds.

Keywords

Cite

@article{arxiv.2512.11538,
  title  = {Virtual invariants from the non-associative Hilbert scheme},
  author = {Gergely Bérczi and Felix Minddal},
  journal= {arXiv preprint arXiv:2512.11538},
  year   = {2025}
}

Comments

60 pages

R2 v1 2026-07-01T08:22:12.238Z