  The properties of rapidly quenched superfluid phase transitions are computed
for two-dimensional Kosterlitz-Thouless (KT) systems. The decay in the
vortex-pair density and the recovery of the superfluid density after a quench
are found by solving the Fokker-Planck equation describing the vortex dynamics,
in conjunction with the KT recursion relations. The vortex density is found to
decay approximately as the inverse of the time from the quench, in agreement
with computer simulations and with scaling theories.
