\begin{table}%t1
\caption{Best-fit values for $\Omega_{\rm{m}}$ and $w$.}\label{tab1}
%\centering
\small
\begin{tabular}{lclr}
\hline \hline
%&&& \\[-8pt]
Test& $\Omega_{\rm{m}}$  & \quad  $w$& $\chi^2/\nu$\\ 
%&&& \\[-8pt]
\hline  
GDDS lookback time & 0.21  & --0.72 & 1.55 \\ 
GDDS lookback time + SNLS & 0.28 & --1.05 & 1.02\\ 
GDDS lookback time + BAO & 0.29 & --1.03 & 1.58\\
lookback time + SNLS + BAO & 0.27 & --1.02 & 1.02\\
\hline 
\end{tabular}
\end{table}