Algebraic Description of Irreducible Representations

Yoshio Ohnuki

Mihail Vladimirovich Karasev, E. M. Novikova

For the three-frequency quantum resonance oscillator, the reducible case, where the frequencies are integer and at least one pair of frequencies has a nontrivial common divisor, is studied. It is shown how the description of the algebra of symmetries of such an oscillator can be reduced to the irreducible case of pairwise coprime integer frequencies. Polynomial algebraic relations are written, and irreducible representations and coherent states are constructed.

J. Grodnik, D. H. Sharp

We continue the investigation of the preceding paper into the irreducible representations of local non-relativistic current algebras. Here, we concentrate on the new features which arise in classifying the representations of the current algebra with regard to particle statistics, and in including internal variables such as spin.

Gerhard C. Hegerfeldt

I. Inaba, Takayoshi Maekawa, TAKUO YAMAMOTO

Infinite-dimensional representations for the system of the two para-Bose operators, which generate the graded Lie algebra (GLA) (Sp(4):4), are constructed by using the irreducible representations (discrete series) of the Lie algebra Sp(4)≊SO(3,2). It is shown that there are four kinds of the irreducible representations of the GLA’s (Sp(4):4), i.e., cases (I), (II), (III), and (IV). Case (I) is described by the three irreducible representations of Sp(4) and corresponds to the para-Bose quantization with real order of the quantization greater than 1 and case (IV) corresponding to the ordinary Bose quantization by the two irreducible representations of Sp(4). Cases (II) and (III), which are described by the four and two irreducible representations of Sp(4), respectively, and cannot be obtained by the method of Fock space, express the representations of the graded Lie algebra (Sp(4):4).