Vanishing of Tor modules and homological dimensions of unions of aCM schemes

JOURNAL OF ALGEBRA

卷:310

Article

Ragusa, Alfio ; Zappala, Giuseppe

关键词: Tor modules;    Cohen-Macaulay rings;    free resolutions;    monomial schemes;   

DOI  :  10.1016/j.jalgebra.2006.10.034

来源: Elsevier

【 摘 要 】

We study the vanishing of some Tor(i)(M, R/J) when R is a local Cohen-Macaulay ring, J any ideal of R with R/J Cohen-Macaulay and M a finitely generated R-module. We use this result to study the homological dimension of unions X boolean OR Y of arithmetically Cohen-Macaulay closed subschemes of P-r. In particular, we show that generically such a homological dimension is the expected one. We give some generalization when one of the two schemes has codimension 2 and we apply this result to the monomial case. (c) 2006 Elsevier Inc. All rights reserved.

【 授权许可】

Free