\right not working in beamer

Question

\documentclass{beamer}
\usepackage{graphics}
\mode<presentation> {
\usepackage{breqn}
\usetheme{Frankfurt}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}



 \begin{align*}
           \bar{v}\sim {|\Omega|\over 4\epsilon DN}\left[1+{\epsilon\over \pi}\log\left(\frac{2}{\epsilon}\right)+\frac{\epsilon}{\pi}\left(-\frac{9N}{5}+2(N-2)\log 2\\+\frac{3}{2}+\frac{4}{N}\mathcal{H}(x_1,\dots,x_N)\right)\right]
        \end{align*}

Issue is \right is not working. I mean on right hand side bracket is closing.

How do I resolve it.

Thanks.