Deformations of half-canonical Gorenstein curves in codimension four

Canonical surfaces in P^4 and Gorenstein algebras in codimension 2

A Characterization of Gorenstein Hilbert Functions in Codimension Four with Small Initial Degree

The main goal of this paper is to characterize the Hilbert functions of all (artinian) codimension 4 Gorenstein algebras that have at least two independent relations of degree four. This includes all codimension 4 Gorenstein algebras whose initial relation is of degree at most 3. Our result shows that those Hilbert functions are exactly the so-called SI-sequences starting with (1, 4, h2, h3, .....

Q-gorenstein Deformations of Nonnormal Surfaces

Let ∆ ⊂ H be the germ of a non-normal surface along a proper curve with smooth components such that the high index points of H are semilog-terminal and the Gorenstein singular points are semi-log-canonical. We describe the sheaf T 1 qG(H) of Q-Gorenstein deformations of H, we show that T 1 qG(H)/(torsion) is a line bundle L on ∆ and we calculate the degree of the restriction of L on every irred...

Some Examples of Gorenstein Liaison in Codimension Three

Gorenstein liaison seems to be the natural notion to generalize to higher codimension the well-known results about liaison o varieties of codimension 2 in projective space. In this paper we study points in P and cuves in P in an attempt to see how far typical codimension 2 results will extend. While the results are satisfactory for small degree, we find in each case examples where we cannot dec...

Deformations of Codimension 2 Toric Varieties

We prove Sturmfels’ conjecture that toric varieties of codimension two have no other flat deformations than those obtained by Gröbner basis theory.