A ESMAEELNEZHAD

In this paper we use ing changed Gorenstein homological dimensions to de ne Cohen-Macaulay injective, projective and at dimensions. To do this we use the amalgamated duplication of the base ring with semi-dualizing ideals. Finiteness of these new dimensions characterize Cohen-Macaulay rings with dualizing ideals.

Semi-dualizing ideal, Amalgamated duplication, Gorenstein homologicaldimension, Cohen-Macaulay homological dimension