English

A theorem of Gordan and Noether via Gorenstein rings

Algebraic Geometry 2023-10-11 v1 Commutative Algebra

Abstract

Gordan and Noether proved in their fundamental theorem that an hypersurface X=V(F)PnX=V(F)\subseteq \mathbb{P}^n with n3n\leq 3 is a cone if and only if FF has vanishing hessian (i.e. the determinant of the Hessian matrix). They also showed that the statement is false if n4n\geq 4, by giving some counterexamples. Since their proof, several others have been proposed in the literature. In this paper we give a new one by using a different perspective which involves the study of standard Artinian Gorenstein K\mathbb{K}-algebras and the Lefschetz properties. As a further application of our setting, we prove that a standard Artinian Gorenstein algebra R=K[x0,,x4]/JR=\mathbb{K}[x_0,\dots,x_4]/J with JJ generated by a regular sequence of quadrics has the strong Lefschetz property. In particular, this holds for Jacobian rings associated to smooth cubic threefolds.

Keywords

Cite

@article{arxiv.2201.07550,
  title  = {A theorem of Gordan and Noether via Gorenstein rings},
  author = {Davide Bricalli and Filippo F. Favale and Gian Pietro Pirola},
  journal= {arXiv preprint arXiv:2201.07550},
  year   = {2023}
}

Comments

21 pages