6 papers
Minimal free resolutions for homogeneous ideals with Betti numbers
Alfio Ragusa, Giuseppe Zappalà
We investigate the standard generalized Gorenstein algebras of homological dimension three, giving a structure theorem for their resolutions. Moreover in many cases we are able to…
Tower sets and other configurations with the Cohen-Macaulay property
Giuseppe Favacchio, Alfio Ragusa, Giuseppe Zappalà
Some well-known arithmetically Cohen-Macaulay configurations of linear varieties in as -configurations, partial intersections and star configurations are generali…
A structure theorem for unions of complete intersections
Alfio Ragusa, Giuseppe Zappala
Using the connections among almost complete intersection schemes, arithmetically Gorenstein schemes and schemes that are union of complete intersections we give a structure theorem…
On the Weak-Lefschetz property for Artinian Gorenstein algebras
Alfio Ragusa, Giuseppe Zappala
We deal with the Weak Lefschetz property (WLP) for Artinian standard graded Gorenstein algebras of codimension We prove that many Gorenstein sequences force the WLP for such a…
On the Weak Lefschetz Property for Hilbert functions of almost complete intersections
Alfio Ragusa, Giuseppe Zappala
It is known that all complete intersection Artinian standard graded algebras of codimension 3 have the Weak Lefschetz Property. Unfortunately, this property does not continue to be…
A Structure Theorem and the Graded Betti Numbers for Almost Complete Intersections
Alfio Ragusa, Giuseppe Zappala
We provide a structure theorem for all almost complete intersection ideals of depth three in any Noetherian local ring. In particular, we find that the minimal generators are the p…