摘要

<正>1引言设A=(aij)∈Cn×n,N={1,2,…,n}.记Ri(A)= sum |aij| from j≠i (i∈N),又记N1=N1(A)={i∈N:0<|aii|≤Ri(A)},N2=N2(A)={i∈N:|aii>Ri(A)}.定义1设A=(aij)∈Cn×n,如果|aii|>Ri(A)(i∈N),则称A为严格对角占优矩阵.严格对角占优矩阵的集合记为D.如果存在n阶正对角矩阵D使得AD∈D,则称A为广义严格对角占优矩阵.广义严格对角占优矩阵的集合记为D.