形式三角矩阵环上的强Ding投射模和强Ding内射模

Strongly Ding projective and strongly Ding injective modules over formal triangular matrix rings

讨论了形式下三角矩阵环T=(AU OB)上的强Ding投射模和强Ding内射模,证明了当UA和BU的平坦维数有限,并且(M1M2)φM是强Ding投射左T-模时,M1是强Ding投射左A-模,φM是单同态,M2/ImφM是强Ding投射左B-模。

Strongly Ding projective and strongly Ding injective modules are investigated over the formal triangular matrix ring T=(AU 0B).It is proved that if both UA and BU have finite flat dimensions,and left T-module(M1M2)φM is strong Ding projective,left A-module M1 is strong Ding projective,φM is a monomorphism,left B-module M2/ImφM is strong Ding projective.