Phase Space Representation

Asao Arai

For each integer n ≥ 2 and a parameter Λ = (θ, η) with θ and η being n × n real anti-symmetric matrices, a quantum phase space (QPS) (or a non-commutative phase space) with n degrees of freedom, denoted QPS n(Λ), is defined, where θ and η are parameters measuring non-commutativity of the QPS. Hilbert space representations of QPS n(Λ) are considered. A concept of quasi-Schrödinger representation of QPS n(Λ) is introduced. It is shown that there exists a general correspondence between representations of QPS n(Λ) and those of the canonical commutation relations with n degrees of freedom. Irreducibility of representations of QPS n(Λ) are investigated. A concept of Weyl representation of QPS n(Λ) is defined. It is proved that every Weyl representation of QPS n(Λ) on a separable Hilbert space is unitarily equivalent to a direct sum of a quasi-Schrödinger representation of the QPS n(Λ) (a uniqueness theorem). Finally representations of QPS n(Λ) which are not unitarily equivalent to any direct sum of a quasi-Schrödinger representation are described.

Miguel Orszag

Hanitriarivo Rakotoson, Raoelina Andriambololona, Ravo Tokiniaina Ranaivoson +1 more

The aim of this paper is to present a study on the representations of coordinate, momentum and dispersion operators in the framework of a phase space representation of quantum mechanics that we have introduced and studied in previous works. We begin in the introduction section with a recall about the concept of representation of operators on wave function spaces. Then, we show that in the case of the phase space representation the coordinate and momentum operators can be represented either with differential operators or with matrices. The explicit expressions of both the differential operators and matrices representations are established. Multidimensional generalization of the obtained results are performed and phase space representation of dispersion operators are given.

Miguel Orszag

Miguel Orszag

Ravo Tokiniaina Ranaivoson, Raoelina Andriambololona, Hanitriarivo Rakotoson

This paper is a continuation of our previous works concerning coordinate, momentum, dispersion operators and phase space representation of quantum mechanics. It deals with the properties of momentum dispersion operator, its representations, eigenvalue equation and its relations with the wavefunctions in the phase space representation. After recalling some results from our previous works, we perform a study concerning the phase space wavefunctions and consider some example of them. Then we establish the eigenvalue equation for the differential operator corresponding to the momentum dispersion operator in the phase space representation. It is shown in particular that any wavefunction in phase space representation is solution of this equation.