  We study finite-size effects on the dynamics of a one-dimensional zero-range
process which shows a phase transition from a low-density disordered phase to a
high-density condensed phase. The current fluctuations in the steady state show
striking differences in the two phases. In the disordered phase, the variance
of the integrated current shows damped oscillations in time due to the motion
of fluctuations around the ring as a dissipating kinematic wave. In the
condensed phase, this wave cannot propagate through the condensate, and the
dynamics is dominated by the long-time relocation of the condensate from site
to site.
