Ideal generation for general reduced projective points

Primarily AI-generated textHuman understanding: some partsmath.AG — Algebraic Geometry

Contributed by Vlado Vojdanovski ↗

Version 1 / Nov 11, 2026 / CC BY 4.0

Abstract

We prove the Ideal Generation Conjecture for general reduced points in projective space over an algebraically closed field of characteristic zero. Equivalently, if the ideal of the points has initial degree D, multiplication by linear forms from degree D to degree D + 1 has maximal rank. The proof combines hyperplane specialization with a construction using two transverse hyperplanes. In the latter construction, motion of their common trace gives the required rank. A uniform induction for all degrees D ≥ 4 reduces the theorem to explicit quadratic and cubic constructions.

Provenance statement

This work was produced as a guided exploration by Open AI Astra agents.

Formalizations

References

  1. A. V. Geramita and F. Orecchia, Minimally generating ideals defining certain tangent cones , J. Algebra 78 (1982), no. 1, 36--57. doi:10.1016/0021-8693(82)90101-6 (https://doi.org/10.1016/0021-8693(82)90101-6).DOI
  2. A. V. Geramita and P. Maroscia, The ideal of forms vanishing at a finite set of points in Pn\mathbb P^n , J. Algebra 90 (1984), no. 2, 528--555. doi:10.1016/0021-8693(84)90188-1 (https://doi.org/10.1016/0021-8693(84)90188-1).DOI
  3. F. Gesmundo, L. Kayser, and S. Telen, Hilbert functions of chopped ideals , J. Algebra 666 (2025), 415--445. doi:10.1016/j.jalgebra.2024.11.017 (https://doi.org/10.1016/j.jalgebra.2024.11.017).DOI
  4. A. Hirschowitz and C. Simpson, La résolution minimale de l'idéal d'un arrangement général d'un grand nombre de points dans Pn\mathbb P^n , Invent. Math. 126 (1996), no. 3, 467--503. doi:10.1007/s002220050107 (https://doi.org/10.1007/s002220050107).DOI
  5. F. Lauze, Rang maximal pour TPnT_{\mathbb P^n} , 1995, arXiv:alg-geom/9506010 (https://arxiv.org/abs/alg-geom/9506010).arXiv
  6. R. Fröberg and C. Löfwall, Koszul homology and Lie algebras with application to generic forms and points , Homology Homotopy Appl. 4 (2002), no. 2, 227--258. doi:10.4310/HHA.2002.v4.n2.a11 (https://doi.org/10.4310/HHA.2002.v4.n2.a11).DOI

Version history

  1. v1 · 39 pagesSubmitted by Vlado VojdanovskiInitial depositCurrentNov 10, 2026