Rotating Skyrmion in 2+1 dimensions

The collective rotation of the Skyrmion in two-dimensional space is considered. In contradistinction to the three-dimensional case, inertial effects do not spoil the hedgehog form and can, therefore, be investigated consistently without great computational difficulty. The energy, the moment of inertia, and the mean radius of the rotating soliton are calculated for a wide range of model parameters. It is found that the ''frozen hedgehog'' treatment-commonly assumed adequate in the Skyrme model on the basis of large N-C (number of colors) arguments-is invalid in a sizable portion of parameter space. The phase shifts associated with radial fluctuations of the rotating soliton are also investigated and are found to be significantly affected by the rotation.