We consider the transverse force on a moving vortex with the acoustic metric
using the ϕ-mapping topological current theory. In the frame of effective
spacetime geometry the vortex appear naturally by virtue of the vortex tensor
in the Lorentz spacetime and we show that it is just the vortex derived with
the order parameter in the condensed matter. With the usual Lagrangian we
obtain the equation of motion for the vortex. At last, we show that the
transverse force on the moving vortex in our equation is just the usual Magnus
force in a simple model.Comment: 11 pages, no figur