Vortex velocities in the O(n) symmetric time-dependent Ginzburg-Landau model

An explicit expression for the vortex velocity held as a function of the order parameter field is derived for the case of point defects in the O(n) symmetric time-dependent Ginzburg-Landau model. This expression is used to find the vortex velocity probability distribution in the Gaussian closure approximation in the case of phase ordering kinetics for a nonconserved order parameter. The velocity scales as L(-1) in scaling regime where L approximate to t(1/2) and t is the time after the quench.