Progress of Theoretical Physics Supplement, no. 172, pp. 21 - 29
In this paper, we study the perturbation problems for the cases of the scalar, electromagnetic, and axial gravitational waves under the traversable Lorentzian wormhole geometry. The general form of the potentials for the Schrödinger type one-dimensional wave equation in terms of spin is found. The quasi normal modes (QNM) of the wormhole perturbation are also calculated by using the WKB approximation. The QNM types for the wormhole are very similar to the black hole cases, since the potentials have the similar types.