On the ring of global sections of the blowing-up along a two-generated ideal

摘要

The effective relations and the relation type of an ideal generated by two regular elements can be expressed in terms of the ring of global sections of the blowing-up along the ideal. As a consequence, we find the minimal overring where the ideal is syzygetic or of linear type. (C) 2008 Elsevier B.V. All rights reserved.