Occurrence of pairwise energy level degeneracies in q,p-oscillator model
  It is demonstrated that a two-parameter deformed oscillator with the deformation parameters q,p such that 0 < q,p \le 1 exhibits the property of "accidental" two-fold (pairwise) energy level degeneracy of the classes E_m=E_{m+1} and E_0=E_{m}. The most general case of degeneracy of q,p-oscillators of the form E_{m+k}=E_m (with k\ge 1 for m\ge 1 or k\ge 2 for m=0) is briefly discussed. 
A.M. Gavrilik, A.P. Rebesh