A Possible Boson Realization of the so(4)- and the so(3,1)-Algebra
  As natural extensions of the boson realizations of the su(2)- and the su(1,1)-algebra, the so(4)- and the so(3,1)-algebras are presented in the form of boson realizations with four kinds of boson operators. For each algebra, two forms are discussed. One is constructed in terms of two sets of the boson operators which play a role of spherical tensor with rank 1/2. The other is based on the ranks 1 and 0. As a possible application, the Runge-Lenz-Pauli vector, which is famous in the hydrogen atom, is derived with some aspects. 
S.Nishiyama (Kochi Univ., Japan), C.Providencia (Univ.de Coimbra,   Portugal), J.da Providencia (Univ.de Coimbra, Portugal),...