Wess-Zumino action for the orbital dynamics of 3He-A
Volovik G. E.
A singularity in the dynamics of the orbital angular momentum in 3Hq-A is explained on the basis of an anomaly which results in a transfer of angular momentum from vacuum to excitations. This process is equivalent to the creation of electron-positron pairs in an electric field. A Wess-Zumino function which is found leads to a source of angular momentum. The presence of a vortex singularity on the Fermi surface in 3He-A leads to a close relationship between the orbital dynamics and the dynamics of vortices.