  We report on a systematic investigation of the critical fluctuations in the
complex conductivity of epitaxially-grown
Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$ films for ${T \lesssim T_c}$ using a
two-coil inductive technique at zero applied field. We observe the static 3D-XY
critical exponent in the superfluid density near $T_{c}$. Linear scaling
analysis close to the critical temperature yields a dynamic critical exponent
of $z = 2.0$ for small drive currents, but non-linear effects are seen to be
important. At $T_{c}$, a non-linear scaling analysis also yields a 3D dynamic
exponent of $z = 2.0$.
