  The post Gaussian effective potential in D=3 dimensions and the Gaussian
effective potential in D=2+epsilon are evaluated for the Ginzburg-Landau theory
of superconductivity. It is shown that, the next order correction to the
Gaussian approximation of the Ginzburg-Landau parameter (kappa) is significant,
whereas contribution from the two dimensionality is rather small. This strongly
indicates that strong correlation plays a more dominant role than the two
dimensionality does in high T_c superconductivity.
