We consider O-sequences that occur for arithmetically Cohen-Macaulay (ACM) schemes X of codimension three in P n. These are Hilbert functions ' of Artinian algebras that are quotients of the coordinate ring of X by a linear system of parameters. Using suitable decompositions of ', we determine the minimal number of generators possible in some degree c for the dening ideal of any such ACM scheme having the given O-sequence. We apply this result to construct Artinian Gorenstein O-sequences ' of codimension 3 such that the poset of all graded Betti sequences of the Artinian Gorenstein algebras with Hilbert function ' admits more than one minimal element. Finally, for all 3- codimensional complete intersection O-sequences we obtain conditions under which the corresponding poset of graded Betti sequences has more than one minimal element.
Looking for minimal graded Betti numbers / RAGUSA ALFIO; ZAPPALA' G. - 49:2(2005), pp. 453-473.
Titolo: | Looking for minimal graded Betti numbers |
Autori interni: | |
Data di pubblicazione: | 2005 |
Rivista: | |
Citazione: | Looking for minimal graded Betti numbers / RAGUSA ALFIO; ZAPPALA' G. - 49:2(2005), pp. 453-473. |
Handle: | http://hdl.handle.net/20.500.11769/7567 |
Appare nelle tipologie: | 1.1 Articolo in rivista |