title: latex subfigures not centered
body: <p>This latex code:</p>
  
  <pre><code>\begin{figure}[H]
   \setlength{\figW}{5cm} % determines the width of the images
        \begin{subfigure}[b]{0.5\textwidth}
             \input{images/eigw_kegel_0.5.tex}
             \caption{}
        \end{subfigure}
        \begin{subfigure}[b]{0.5\textwidth}
             \input{images/eigw_kegel_0.05.tex}
             \caption{}
        \end{subfigure} \\
        \begin{subfigure}[b]{0.5\textwidth}
             \input{images/eigv_norm_kegel_0.5.tex}
             \caption{}
        \end{subfigure}
        \begin{subfigure}[b]{0.5\textwidth}
             \input{images/eigv_norm_kegel_0.05.tex}
             \caption{}
        \end{subfigure}
    \caption{(a) and (b): $\lambda_1(\VM{\omega})$ and 
    $\lambda_2(\VM{\omega})$ with $\omega_1 = 0.5$ (left) and $\omega_1 = 
    0.05$ (right), (c) and (d): norm of $\pderiv{\VM{x}_1(\VM{\omega})} 
     {\omega_2}$  with $\omega_1= 0.5$ (left) and $\omega_1= 0.05$ (right)}
    \end{figure}
  </code></pre>
  
  <p>gives me the following output:
  <a href="https://i.stack.imgur.com/XuALI.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/XuALI.png" alt=""></a></p>
  
  <p>I would like to have the following output (made it using paint). How to adapt the latex-code so that I get this result? </p>
  
  <p><a href="https://i.stack.imgur.com/ebbk7.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ebbk7.png" alt="enter image description here"></a></p>