Problem with big equations (matrices)

Question

I have used LaTeX for writing my paper. The template of journal is in two columns and I have some problems with breaking large equations (especially matrices). Would you please guide me?

Details: I have used the multiline environment but the brackets related to matrix is small.

In another attempt I used equation environment but \\ does not work to go from the upper side of matrix to the lower part of the matrix.

I have written the equation in two structures:

1:

\begin{equation}\label{eq:eq10}
\left[
\begin{matrix} {\bar A}{x_1} + {\tilde B}{x_2} + {\hat C}{x_3} & {P{{\bar A}_{1i}}} & \cdots \\
* & { - (1 - {\mu _1}){P_1}} & \cdots \\
\vdots & \vdots & \ddots \\
* & * & \cdots \\
* & * & \cdots \\
* & * & \cdots
\end{matrix} \\
\qquad \qquad \begin{matrix} {P{{\bar A}_{si}}} & {P{{\bar B}_i}} & {{{\bar C}^T}} \\
0 & 0 & 0 \\
\vdots & \vdots & \vdots \\
{ - (1 - {\mu _s}){P_s}} & 0 & 0 \\
* &{ - {\gamma ^2}I} & {{{\bar D}^T}} \\
* & * & { - I} \end{matrix}
\right] < 0
\end{equation}

This solution has the problem that \\ after first \end{matrix} does not work. I mean it does not force the remaining of the equation to go to the next line.

2:

\begin{multline}
\Bigg[
%\left(
\begin{matrix} {\bar A}{x_1} + {\tilde B}{x_2} + {\hat C}{x_3} & {P{{\bar A}_{1i}}} & \cdots \\
* & { - (1 - {\mu _1}){P_1}} & \cdots \\
\vdots & \vdots & \ddots \\
* & * & \cdots \\
* & * & \cdots \\
* & * & \cdots
\end{matrix} \\
%\right
%\left
\begin{matrix} {P{{\bar A}_{si}}} & {P{{\bar B}_i}} & {{{\bar C}^T}} \\
0 & 0 & 0 \\
\vdots & \vdots & \vdots \\
{ - (1 - {\mu _s}){P_s}} & 0 & 0 \\
* &{ - {\gamma ^2}I} & {{{\bar D}^T}} \\
* & * & { - I} \end{matrix}
\Bigg] < 0
%\right)
\end{multline}

This is the second solution. It is well broken in two sub-matrices but it has the problem that the brackets of the matrix are very small for this big matrix, even with the \Bigg command.

How should I fix this problem?

Answer 1

If amsmath is not forbidden, a solution (rather strange) may be as follows.

\documentclass{article}

\usepackage{amsmath}
\begin{document}


%\begin{equation}\label{eq:eq10}
\begin{gather}\label{eq:eq10}
\left[
\begin{matrix} {\bar A}{x_1} + {\tilde B}{x_2} + {\hat C}{x_3} & {P{{\bar A}_{1i}}} & \cdots \\
* & { - (1 - {\mu _1}){P_1}} & \cdots \\
\vdots & \vdots & \ddots \\
* & * & \cdots \\
* & * & \cdots \\
* & * & \cdots
\end{matrix}
\right.
 \nonumber\\
\qquad \qquad\left. \begin{matrix} {P{{\bar A}_{si}}} & {P{{\bar B}_i}} & {{{\bar C}^T}} \\
0 & 0 & 0 \\
\vdots & \vdots & \vdots \\
{ - (1 - {\mu _s}){P_s}} & 0 & 0 \\
* &{ - {\gamma ^2}I} & {{{\bar D}^T}} \\
* & * & { - I} \end{matrix}
\right] < 0
%\end{equation}
\end{gather}

\end{document}