  We demonstrate that in the strong coupling limit (the superconducting gap
$\Delta$ is as large as the chemical potential $\mu$), which is relevant to the
high-$T_c$ superconductivity, the correlation corrections to the gap and
critical temperature are about 10\% of the corresponding mean field
approximation values. For the weak coupling ($\Delta \ll \mu$) the correlation
corrections are very large: of the order of 100\% of the corresponding mean
field values.
