Gorenstein Liaison and ACM Sheaves

Casanellas, Marta; Drozd, Elena; Hartshorne, Robin

Gorenstein Liaison and ACM Sheaves

Authors

Casanellas, Marta

Drozd, Elena

Hartshorne, Robin

Description

We study Gorenstein liaison of codimension two subschemes of an arithmetically Gorenstein scheme X. Our main result is a criterion for two such subschemes to be in the same Gorenstein liaison class, in terms of the category of ACM sheaves on X. As a consequence we obtain a criterion for X to have the property that every codimension 2 arithmetically Cohen-Macaulay subscheme is in the Gorenstein liaison class of a complete intersection. Using these tools we prove that every arithmetically Gorenstein subscheme of $\mathbb{P}^n$ is in the Gorenstein liaison class of a complete intesection and we are able to characterize the Gorenstein liaison classes of curves on a nonsingular quadric threefold in $\mathbb{P}^4$.
28 pages