On a dynamical symmetry group of the relativistic linear singular   oscillator
  An exact approach for the factorization of the relativistic linear singular oscillator is proposed. This model is expressed by the finite-difference Schr\"odinger-like equation. We have found finite-difference raising and lowering operators, which are with the Hamiltonian operator form the close Lie algebra of the $SU(1, 1)$ group. 
S.M. Nagiyev, E.I. Jafarov and R.M. Imanov