\begin{table}
%\caption{This table shows the temporal evolution of the eigenvalues
%and eigenvectors as a function of the look-back time in Gyr (column
%1). The three eigenvalues are in columns (2) to (4) and the
%corresponding eigenvectors are in columns (5) through (13). The
%headers are self explanatory. We have highlighted the most negative
%values (column 4) and the corresponding eigenvectors (column 11
%through 13) for all values of the look-back time at  which the most
%negative eigenvalue keeps its  sign.}
% %\centerline {\begin{tabular}{|crrrrrrrrrrrr|}
% \hline
%$t_{{\rm lb}}$ & $\lambda _1 $ & $\lambda _2 $ & $\lambda _3 $ & $n_{{\rm x}}^{\left( {\lambda _1 } \right)} $ &  $n_{\rm y}^{\left( {\lambda _1 } \right)} $ &  $n_{\rm z}^{\left( {\lambda _1 } \right)} $ & $n_{\rm x}^{\left( {\lambda _2 } \right)} $ &  $n_{\rm y}^{\left( {\lambda _2 } \right)} $ &  $n_{\rm z}^{\left( {\lambda _2 } \right)} $ & $n_{\rm x}^{\left( {\lambda _3 } \right)} $ &  $n_{\rm y}^{\left( {\lambda _3 } \right)} $ &  $n_{\rm z}^{\left( {\lambda _3 } \right)} $ \\
%\hline
%13.3 &  0.0125 & -0.0049 & -0.0076       &  0.310 &  0.507 &  0.804 &  0.934 & -0.008 & -0.356 &  0.174      & -0.862       &  0.476 \\
%12.3 & 0.0058 &  0.0001 &  -0.0060 & -0.266      &  0.411       &  0.872       &  0.944 &  0.292 &  0.151 &  0.192 & -0.864 &  0.465  \\
%11.0 & 0.0031 &  0.0008 &  -0.0038  &  0.941      &  0.052       & -0.334      &  0.265 &  0.498 &  0.826 &  0.209 & -0.866 &  0.455 \\
%9.5  &  0.0030 & -0.0002 & {\it -0.0028} &  0.971 &  0.235 & -0.043 & -0.066 &  0.436 &  0.897 & {\it 0.230} & {\it -0.868}   &  {\it 0.439} \\
%7.9  &  0.0030 & -0.0006 & {\it -0.0024} &  0.954 &  0.297 &  0.026 & -0.146 &  0.390 &  0.909 & {\it 0.259} & {\it -0.871} & {\it 0.416} \\
%6.2  &  0.0030 & -0.0007 & {\it -0.0023} &  0.939 &  0.341 &  0.045 & -0.171 &  0.346 &  0.922 & {\it 0.299} & {\it -0.873} & {\it 0.384} \\
%4.6  &  0.0033 & -0.0008 & {\it -0.0024} &  0.919 &  0.391 &  0.050 & -0.175 &  0.292 &  0.940 & {\it 0.353} & {\it -0.873} & {\it 0.336} \\
%3.0  &  0.0037 & -0.0009 & {\it -0.0028} &  0.887 &  0.458 &  0.059 & -0.171 &  0.208 &  0.963 & {\it 0.429} & {\it -0.864} & {\it 0.263} \\
%1.4  &  0.0046 & -0.0010 & {\it -0.0036} & -0.829 & -0.551 & -0.097 & -0.158 &  0.065 &  0.985 & {\it 0.536} & {\it -0.832} & {\it 0.141}\\
%0.0  &  0.0065 & -0.0017 & {\it -0.0047} & -0.738 & -0.657 & -0.151 & -0.064 & -0.154 &  0.986 & {\it 0.671} & {\it -0.738} & {\it-0.071} \\
%\hline
%\end{tabular}}
%\label{Tabella04}
%\end{table}