Mr. Johnson et Kn. Raghavan, COHEN-MACAULAYNESS OF BLOW-UPS OF HOMOGENEOUS WEAK D-SEQUENCES, Proceedings of the American Mathematical Society, 123(7), 1995, pp. 1991-1994
Let R be a homogeneous Cohen-Macaulay algebra over a field, and let I
be an ideal generated by a homogeneous weak d-sequence. We show, under
reasonable conditions on the sequence, that the graded ring gr(M)R[lt
] of the Rees algebra R[It] = X(i greater than or equal to 0) I-i is C
ohen-Macaulay. In particular we obtain the Cohen-Macaulayness of the b
low-up ring R[It].