# can I draw an arrow between 2 matrices?

\begin{bmatrix}
{2 \boldsymbol A \boldsymbol{A} ^{*}} & {\boldsymbol{O}} \\
{\boldsymbol{O}} & {3 \boldsymbol B \boldsymbol B^{*}}
\end{bmatrix}=
\begin{bmatrix}
{4 \boldsymbol{E}} & {} \\
{} & {9 \boldsymbol{E}}
\end{bmatrix}


I want to draw a curve,from 2 \boldsymbol A \boldsymbol{A} ^{*} to 4 \boldsymbol{E}, it could be better if the curve can addon text/formula.how to achieve this?

• Look at this answer. It's for text, not math, but it should work the same in math mode. There will be many more examples. You can find them by searching, for example like this. Commented Aug 28, 2019 at 12:44

You can use nicematrix which will create Tikz nodes for you and then, draw the arrow with a Tikz instruction.

\documentclass{article}
\usepackage{nicematrix,tikz}

\NiceMatrixOptions{renew-dots,renew-matrix}

\begin{document}

$\begin{bmatrix}[name=A] 2 \boldsymbol{A} \boldsymbol{A}^{*} & \boldsymbol{O} \\ \boldsymbol{O} & 3 \boldsymbol{B} \boldsymbol{B}^{*} \end{bmatrix}= \begin{bmatrix}[name=B] 4 \boldsymbol{E} & \\ & 9 \boldsymbol{E} \end{bmatrix}$
\tikz [remember picture, overlay] \draw [red,->] (A-1-1) to [bend left=45] (B-1-1) ;

\end{document}