How to fit a large equation where the text describes it in an article of double column format?

Question

Using this code, I am facing the problem shown in the right side of the picture. The Equation spans beyond the page margin on the right.

\documentclass[aps,prl,reprint]{revtex4-1}
\usepackage{blindtext}
\usepackage{graphicx}
\usepackage{graphics}
\usepackage{bm}        % for math
\usepackage{verbatim}   % for math
\usepackage{amsfonts}
\usepackage{amsmath}
\usepackage{bm}
\usepackage{amssymb}
\usepackage{adjustbox}
\DeclareMathOperator{\RE}{Re}
\DeclareMathOperator{\IM}{Im}
\newcommand{\revtex}{REV\TeX\ }
\newcommand{\classoption}[1]{\texttt{#1}}
\newcommand{\macro}[1]{\texttt{\textbackslash#1}}
\newcommand{\m}[1]{\macro{#1}}
\newcommand{\env}[1]{\texttt{#1}}
\setlength{\textheight}{9.5in}
\newenvironment{psmallmatrix}
  {\left[\begin{smallmatrix}}
  {\end{smallmatrix}\right]}
\begin{document}
\begin{align*}
\tiny{var(\mathbf{\theta^* - \hat{\theta^*}})} \ge
\begin{psmallmatrix}
   2 & 0 & 0 & 0 & 0  \\[3ex]
   0 & 2 &  0 & 0 & 0 \\[3ex]
  0  &  0 & 2 & 0 & 0\\[3ex]
  0 &  0 & 0  & 2 & 0 \\[3ex]
  0 & 0 & 0 & 0 & 1
  \end{psmallmatrix}
 \begin{psmallmatrix}
   \tiny{J_{11}^{-1}} & \tiny{0} & \tiny{\Delta_1^{-1}} & -\Delta_1^{-1}J_{14}{J_{24}}^{-1} & 0  \\[3ex]
   0 & J_{22}^{-1} &  {-J_{24}}^{-1}J_{23}\Delta_1^{-1} & {J_{24}}^{-1}+{J_{24}}^{-1}J_{23}\Delta_1^{-1}J_{14}J_{24}& 0 \\[3ex]
  \Delta_2^{-1}  & -\Delta_2^{-1}J_{32}J_{42}^{-1} & J_{33}^{-1} & 0 & 0\\[3ex]
 \tiny{-J_{42}^{-1}J_{41}\Delta_2^{-1}} & {J_42}^{-1} + {J_42}^{-1}J_{41}\Delta_2^{-1}J_{32}{J_42}^{-1}  & 0  & J_{44}^{-1} & 0 \\[3ex]
  0 & 0 & 0 & 0 & 1
  \end{psmallmatrix}
\end{align*}

\end{document}

I tried using the

\begin{figure*}[b]%% over both colum
\begin{align*}

\nonumber
\end{align*}
\end{figure*}

But the problem with this command is that the equation / matrix appears at the bottom of the page whereas, the text describing / referencing to this Equation is somewhere else in the document. This approach is very unappealing visually. So, is there a command so that the matrix / equation appears with the text and also fits in the page for an article in double column.

Question : How can I break the two column format in specific areas where an Equation extends beyond the page margin? I have several such large matrices in my document. I am using WinEdit7.1 Editor.

UPDATE: This is the output that I am getting based on the answer. The problem still remains as can be seen from the picture; the equation goes beyond the margin on right side.

Answer 1

You can't fit that beast in a narrow column.

Unless you decide to go for a figure* environment, you can use symbolic names for the big expressions. Very small expressions are difficult to read and should only be used in emergency situations.

\documentclass[aps,prl,reprint]{revtex4-1}

\usepackage{amsmath}
\usepackage{bm} % after amsmath!
\usepackage{amssymb}

\usepackage{lipsum} % for the context

\DeclareMathOperator{\RE}{Re}
\DeclareMathOperator{\IM}{Im}

\newenvironment{psmallmatrix}
  {\left[\begin{smallmatrix}}
  {\end{smallmatrix}\right]}

\begin{document}

\lipsum*[2]
\begin{equation*}
\mathit{var}(\mathbf{\theta^* - \widehat{\theta^*}}) \ge
\begin{bmatrix}
  2 & 0 & 0 & 0 & 0 \\
  0 & 2 & 0 & 0 & 0 \\
  0 & 0 & 2 & 0 & 0 \\
  0 & 0 & 0 & 2 & 0 \\
  0 & 0 & 0 & 0 & 1
\end{bmatrix}
\begin{bmatrix}
  a_{11} & 0      & a_{13} & a_{14} & 0 \\
  0      & a_{22} & a_{23} & a_{24} & 0 \\
  a_{31} & a_{32} & a_{33} & 0      & 0 \\
  a_{41} & a_{42} & 0      & a_{44} & 0 \\
  0      & 0      & 0      & 0      & 1
  \end{bmatrix}
\end{equation*}
where
\begin{align*}
a_{11}&=J_{11}^{-1} \\
a_{13}&=\Delta_1^{-1} \\
a_{14}&=-\Delta_1^{-1}J_{14}^{}J_{24}^{-1}\\
a_{22}&=J_{22}^{-1}\\
a_{23}&=-J_{24}^{-1}J_{23}^{}\Delta_1^{-1}\\
a_{24}&=J_{24}^{-1}+J_{24}^{-1}J_{23}^{}\Delta_1^{-1}J_{14}^{}J_{24}^{}\\
a_{31}&=\Delta_2^{-1}\\
a_{32}&=-\Delta_2^{-1}J_{32}^{}J_{42}^{-1}\\
a_{33}&=J_{33}^{-1}\\
a_{41}&=-J_{42}^{-1}J_{41}^{}\Delta_2^{-1}\\
a_{42}&=J_{42}^{-1} + J_{42}^{-1}J_{41}^{}\Delta_2^{-1}J_{32}^{}J_{42}^{-1}\\
a_{44}&=J_{44}^{-1}
\end{align*}
\lipsum[3-9]

\end{document}

Answer 2

Revtex defines the widetext environment for such exceptional situations. It interrupts the two column mode and balances the text above the environment:

\documentclass[aps,prl,reprint]{revtex4-1}
\usepackage{blindtext}
\usepackage{graphicx}
\usepackage{graphics}
\usepackage{bm} % for math
\usepackage{verbatim} % for math
\usepackage{amsfonts}
\usepackage{amsmath}
\usepackage{bm}
\usepackage{amssymb}
\usepackage{adjustbox}
\DeclareMathOperator{\RE}{Re}
\DeclareMathOperator{\IM}{Im}
\newcommand{\revtex}{REV\TeX\ }
\newcommand{\classoption}[1]{\texttt{#1}}
\newcommand{\macro}[1]{\texttt{\textbackslash#1}}
\newcommand{\m}[1]{\macro{#1}}
\newcommand{\env}[1]{\texttt{#1}}
\setlength{\textheight}{9.5in}
\newenvironment{psmallmatrix}
  {\left[\begin{smallmatrix}}
  {\end{smallmatrix}\right]}
\usepackage{showframe}
\renewcommand\ShowFrameLinethickness{0.3pt}
\usepackage{lipsum}

\begin{document}

\lipsum[1-3]
\begin{widetext}
\begin{align*}
var(\mathbf{\theta^* - \hat{\theta^*}}) \ge
\begin{psmallmatrix}
   2 & 0 & 0 & 0 & 0 \\[3ex]
   0 & 2 & 0 & 0 & 0 \\[3ex]
  0 & 0 & 2 & 0 & 0\\[3ex]
  0 & 0 & 0 & 2 & 0 \\[3ex]
  0 & 0 & 0 & 0 & 1
  \end{psmallmatrix}
 \begin{psmallmatrix}
   J_{11}^{-1} & 0 & \Delta_1^{-1} & -\Delta_1^{-1}J_{14}{J_{24}}^{-1} & 0 \\[3ex]
   0 & J_{22}^{-1} & {-J_{24}}^{-1}J_{23}\Delta_1^{-1} & {J_{24}}^{-1}+{J_{24}}^{-1}J_{23}\Delta_1^{-1}J_{14}J_{24}& 0 \\[3ex]
  \Delta_2^{-1} & -\Delta_2^{-1}J_{32}J_{42}^{-1} & J_{33}^{-1} & 0 & 0\\[3ex]
 -J_{42}^{-1}J_{41}\Delta_2^{-1} & {J_42}^{-1} + {J_42}^{-1}J_{41}\Delta_2^{-1}J_{32}{J_42}^{-1} & 0 & J_{44}^{-1} & 0 \\[3ex]
  0 & 0 & 0 & 0 & 1
  \end{psmallmatrix}
\end{align*}
\end{widetext}
\lipsum[4-6]

\end{document}

Answer 3

Note you can not use size commands in math mode, and if you use them in text they do not take an argument, the syntax is \tiny abc not \tiny{abc}

You can always just leave a space in the second column. You need to leave it until the final edit to tweak the position, but

\documentclass[aps,prl,reprint]{revtex4-1}
\usepackage{amsfonts}
\usepackage{amsmath}
\DeclareMathOperator{\RE}{Re}
\DeclareMathOperator{\IM}{Im}
\newcommand{\revtex}{REV\TeX\ }
\newcommand{\classoption}[1]{\texttt{#1}}
\newcommand{\macro}[1]{\texttt{\textbackslash#1}}
\newcommand{\m}[1]{\macro{#1}}
\newcommand{\env}[1]{\texttt{#1}}
\setlength{\textheight}{9.5in}
\newenvironment{psmallmatrix}
  {\left[\begin{smallmatrix}}
  {\end{smallmatrix}\right]}
\DeclareMathOperator\var{var}
\begin{document}

\par\noindent X\dotfill X
\par\noindent X\dotfill X
\par\noindent X\dotfill X

\begin{flushleft}
\makebox[0pt][l]{$
\var(\mathbf{\theta^* - \hat{\theta^*}}) \ge
\begin{psmallmatrix}
   2 & 0 & 0 & 0 & 0  \\[3ex]
   0 & 2 &  0 & 0 & 0 \\[3ex]
  0  &  0 & 2 & 0 & 0\\[3ex]
  0 &  0 & 0  & 2 & 0 \\[3ex]
  0 & 0 & 0 & 0 & 1
  \end{psmallmatrix}
 \begin{psmallmatrix}
   J_{11}^{-1} & 0 & \Delta_1^{-1} & -\Delta_1^{-1}J_{14}{J_{24}}^{-1} & 0  \\[3ex]
   0 & J_{22}^{-1} &  {-J_{24}}^{-1}J_{23}\Delta_1^{-1} & {J_{24}}^{-1}+{J_{24}}^{-1}J_{23}\Delta_1^{-1}J_{14}J_{24}& 0 \\[3ex]
  \Delta_2^{-1}  & -\Delta_2^{-1}J_{32}J_{42}^{-1} & J_{33}^{-1} & 0 & 0\\[3ex]
 -J_{42}^{-1}J_{41}\Delta_2^{-1} & {J_42}^{-1} + {J_42}^{-1}J_{41}\Delta_2^{-1}J_{32}{J_42}^{-1}  & 0  & J_{44}^{-1} & 0 \\[3ex]
  0 & 0 & 0 & 0 & 1
  \end{psmallmatrix}
$}
\end{flushleft}

\par\noindent X\dotfill X
\par\noindent X\dotfill X
\par\noindent X\dotfill X
\par\noindent X\dotfill X
\par\noindent X\dotfill X

\vspace*{11\baselineskip}

\par\noindent X\dotfill X
\par\noindent X\dotfill X
\par\noindent X\dotfill X

\end{document}