考虑矩阵方程组{A1XA1^*+B1YB1^*=C1 A2XA2^*+B2YB2^*=C2,其中Ci=Ci^*,i=1,2。通过矩阵秩的方法得到了该方程组有公共Hermitian解x,y的一种新的存在性条件,以及方程组有单独的公共Hermitian解x或y的充分必要条件。
The matrix equations are {A1XA1^*+B1YB1^*=C1 A2XA2^*+B2YB2^*=C2, studied, whereCi=Ci^*,i=1,2. By the rank of matrix,a necessary and sufficient condition is given for the matrix equations to have a pair of common Hermitian solutions X and Y. As a consequence, we have derived the conditions for the matrix equations to have Hermitian solution X or Y re- spectively by ranks.