Surface spin waves in the superfluid A phase of 3He

A generalization of the Leggett--Takagi theory of NMR is presented in the case when the order parameter in the equilibrium is space dependent. The equations of spin dynamics are solved and the frequencies and damping in the cases of specular and diffuse scattering of quasiparticles from the plane wall are found. It is shown that in the case of diffuse scattering, surface spin waves exist. The contribution of this mode to the absorption of a uniform rf field is found