\begin{table}%t3
\caption{\label{tb:alphadelta}Predicted slopes and comparison with our observed values $\delta_1 = 0.78\pm0.02$ and $\delta_2 = 1.44 \pm
0.04$ for different models (all in the framework of a spherical relativistic fireball). $\nui$ and $\nuc$ are the
standard injection and cooling frequencies (defined e.g. in Sari \etal \cite{SPN98}). $\nuo$ spans the whole observed
band, from optical ($\sim$$10^{14}$~Hz) to \Xray{} ($\sim$$10^{18}$~Hz).}
%\centering
\begin{tabular}{llllll}
\hline\hline\noalign{\smallskip}
Frequencies       & Ambient  & Electron     & Predicted      & \multicolumn{2}{l}{Discrepance}  \\
order             & density  & index $p$    & slope $\delta$ & $\delta_1$  & $\delta_2$  \\ \noalign{\smallskip}\hline\noalign{\smallskip}
$\nuc<\nui<\nuo$  & uniform  &$1.6 \pm 0.1 $&$0.92 \pm 0.02 $&  7.5$\sigma$ & 13$\sigma$  \\
                  & wind     &$1.6 \pm 0.1 $&$0.95 \pm 0.01 $&  9.0$\sigma$ & 12$\sigma$  \\
$\nui<\nuo<\nuc$  & uniform  &$2.6 \pm 0.1 $&$ 1.2 \pm 0.1  $ & 4.3$\sigma$ & 2.4$\sigma$ \\
                  & wind     &$2.6 \pm 0.1 $&$ 1.7 \pm 0.1  $ & 9.3$\sigma$ & 2.6$\sigma$ \\
$\nui<\nuc<\nuo$  & uniform  &$1.6 \pm 0.1 $&$0.92 \pm 0.02 $&  7.5$\sigma$ & 13$\sigma$  \\
                  & wind     &$1.6 \pm 0.1 $&$0.95 \pm 0.01 $&  9.0$\sigma$ & 12$\sigma$  \\ \hline
\end{tabular}
\end{table}