\documentclass[12pt]{article}
\usepackage{amsmath,amssymb,amsfonts}
\begin{document}
We study $SL(2;R)$ duality of the noncommutative DBI Lagrangian and the symmetric conditions of this theory under the above group. By introducing some consistent relations we see that the noncommutative (ordinary) DBI Lagrangian and its $SL(2;R)$ dual theory are dual of each other. Therefore, we find some $SL(2;R)$ invariant equations. In this case the noncommutativity parameter, its $T$-dual and its $SL(2;R)$ dual versions are expressed in terms of each other. Furthermore, we show that on the effective variables, $T$-duality and $SL(2;R)$ duality do not commute.
\end{document}