Beamer-Using resizebox changes the position of an item in itemize

Question

I am creating a presentation using beamer. In an itemize environment, I am using resizebox in particular item. When I use it, the position of the bullet changes, as seen in the next image

My code is

\documentclass[10pt]{beamer}
\setbeamerfont{headline}{size=\footnotesize}
\usetheme{Ilmenau}
\usepackage{amsmath,amssymb}

\begin{document}
\section{Section}
\subsection{Subsection}
\begin{frame}
 \begin{itemize}
  \item Cross section $A(x,y)B$ : Definition of cross section
  \item %\resizebox{\textwidth}{!}{
        $\dfrac{d \sigma}{d \Omega}(E,\theta) = \dfrac{Y}{N \left(Q\Omega\right)}\;,        
        \begin{array}{ll}
         Y : & \text{Y}\\
         N : & \text{N}\\
         Q : & \text{Q}\\
         \Omega : & \text{Angle}
        \end{array}
        $
        %}
  \item How  : Like that
 \end{itemize}
\end{frame}
\end{document}

Any idea on why is this happening and how can it be fixed?

Answer 1

Your resized box is too wide. \textwidth is the width of the whole text including the itemize bullet. Use something like 0.999\linewidth instead. Note there is a difference between \textwidth and \linewidth. Unfortunately I do not know why the factor 0.999 is necessary.

\documentclass[10pt,huge]{beamer}
\setbeamerfont{headline}{size=\footnotesize}
\usetheme{Ilmenau}
\usepackage{amsmath,amssymb,lmodern}

\begin{document}
\section{Section}
\subsection{Subsection}
\begin{frame}
 \begin{itemize}
  \item Cross section $A(x,y)B$ : Definition of cross section
  \item \resizebox{.999\linewidth}{!}{%
        $\dfrac{d \sigma}{d \Omega}(E,\theta) = \dfrac{Y}{N \left(Q\Omega\right)}\;,        
        \begin{array}{ll}
         Y : & \text{Y}\\
         N : & \text{N}\\
         Q : & \text{Q}\\
         \Omega : & \text{Angle}
        \end{array}%
        $%
        }%
  \item How  : Like that
 \end{itemize}
\end{frame}
\end{document}

Alternatively you can hide the width of the box using \makebox

\documentclass[10pt,huge]{beamer}
\setbeamerfont{headline}{size=\footnotesize}
\usetheme{Ilmenau}
\usepackage{amsmath,amssymb,lmodern}

\begin{document}
\section{Section}
\subsection{Subsection}
\begin{frame}
 \begin{itemize}
  \item Cross section $A(x,y)B$ : Definition of cross section
  \item \makebox[0pt][l]{\resizebox{\linewidth}{!}{%
        $\dfrac{d \sigma}{d \Omega}(E,\theta) = \dfrac{Y}{N \left(Q\Omega\right)}\;,        
        \begin{array}{ll}
         Y : & \text{Y}\\
         N : & \text{N}\\
         Q : & \text{Q}\\
         \Omega : & \text{Angle}
        \end{array}%
        $%
        }}%
  \item How  : Like that
 \end{itemize}
\end{frame}
\end{document}