\begin{table}%t3
%\centering
\par
\caption{Values found for the slopes~$s$ (see Sect.~\ref{sec:pmax}) and~$sv$ (see Sect.~\ref{sec:vmax}). "Method'' is the method considered for the calculations of~${\cal P}$.}\label{tab:slopes}
\begin{tabular}{cccc}
\hline\hline
Method &    $\chi_k$ & $s$  & $sv$   \\
\hline
direct          &  ---         & 3.4   & --- \\
semi-analytical &  Gaussian    & 3.1 &  1.0\\
semi-analytical &  exponential & 3.0 &  0.9\\
semi-analytical &  Lorentzian  & 2.6 &  0.7\\
\hline
\end{tabular}
\end{table}