For an ideal I of a Noetherian local ring (R, m, k) one hasβR1(I) -β0R(I) ≥-1. It is demonstrated that some residual intersections of an ideal I for whichβ1R(I) -β0R(I) = -1 or 0 are perfect.
文摘For an ideal I of a Noetherian local ring (R, m, k) one hasβR1(I) -β0R(I) ≥-1. It is demonstrated that some residual intersections of an ideal I for whichβ1R(I) -β0R(I) = -1 or 0 are perfect.