On Buchsbaum rings obtained by gluing

Abstract

Let A be a Noetherian local ring with maximal ideal m. In 1973 J. Barshay [1] showed that, if A is a Cohen-Macaulay ring, then so is the Rees algebra R(q) = ⊕n≧0qn for every parameter ideal q of A (cf. p. 93, Corollary). Recently the author and Y. Shimoda [5] have proved that the Rees algebra R(q) is a Cohen-Macaulay ring for every parameter ideal q of A if and only if(#) A is a Buchsbaum ring and for i ≠ 1, dim A.