\documentclass[twocolumn]{revtex4}
\usepackage{graphicx}
\begin{document}

\title{An example of ReVTeX4}
\author{D.V.~Fedorov}
\affiliation{IFA, Aarhus University}
\begin{abstract}
A short example of RevTex usage.
\end{abstract}
\maketitle

\section{Introduction}
Hello world.
Here is some math: $\alpha^2=\beta^2+\gamma^2$.
	\begin{equation}\label{eq:a}
\frac{\partial}{\partial x}y = y \,.
	\end{equation}

This equation has number~(\ref{eq:a}).


\end{document}
