Wigner rotations and little groups
Wigner’s little groups are the subgroups of the Poincaré group whose transformations leave the four-momentum of a given particle invariant. For a relativistic particle in motion the little group is a boosted rotation. On the other hand, the kinematical effect of two non-colinear Lorentz boosts is another boost preceded or follwed by a rotation, which is called the Wigner rotation. It is shown that there is always a Wigner rotation for a given little group rotation. The differences between those two rotations are clearly demonstrated and some interesting physical applications are presented.
KeywordsWigner’s little groups Wigner rotations
PACS42.55.Ah 11.30.Cp 42.15.Eq
- 7.S. Ba§kal and Y.S. Kim, math-ph/0210056, to appear in Phys. Rev. E 67 (2003).Google Scholar