1 Introduction
Consider the coupled algebraic Riccati equation (CARE) in the unknown : \begin{equation*} A_{i}^{\prime}X_{i}+X_{i}A_{i}-X_{i}B_{i}R_{i}^{-1}B_{i}^{\prime} X_{i}+C_{\mathrm{i}}^{\prime}C_{\mathrm{i}}+\displaystyle \sum_{j=1}^{N}\lambda_{\mathrm{i}j}X_{j}=0,\ \mathrm{i}=1, \ldots, N \tag{1} \end{equation*}
where is given, and and are matrices that belong to given collections of real matrices and , Equation (1) arises in the linear quadratic (LQ) control problem of Markov jump linear systems (MJLS).