\begin{table}%tb1
\caption{Coefficients $C_1$ and $C_2$ for the calculation of $\left\la
  N^2_{00}\right\ra$.}  
\label{tbl_coeff} 
%\centering
\small
\begin{tabular}{c c c c }
 \hline\hline
& Isotropic & Cosine power law & Sine power law\\
\hline
%& & \\[-1.5ex]
\large{$C_1$} & \Large{$\frac{2}{5}$} & \Large{$\frac{6(p+1)}{(p+3)(p+5)}$} &
\Large{$\frac{3(p+2)}{(p+3)(p+5)}$} \\
%& & \\[-1ex]
\large{$C_2$} &  \Large{$\frac{2}{5}$} & \Large{$\frac{6}{(p+3)(p+5)}$} &
 \Large{$\frac{3 
  (p+2)(p+4)}{4(p+3)(p+5)}$} \\[1ex]
\hline
\end{tabular} 
\end{table}