Symmetry Lie algebra of the Dirac oscillator

Recently the name Dirac oscillator was given to a Dirac equation in which both the momenta and the coordinates appear linearly. In the non-relativistic limit, the equation satisfied by the large components is that of a standard harmonic oscillator plus a very strong spin-orbit coupling term. This equation can be solved exactly, and the spectrum presents degeneracies which on occasions are finite and on others infinite The authors show that the symmetry Lie algebra is so(4)(+)so(3,1) and find its generators explicitly.