Reduction of the representations of the generalised Poincare algebra by the Galilei algebra

Abstract

The realisations of all classes of unitary irreducible representations of the generalised Poincare group P(1,4) have been found in a basis in which the Casimir operators of its important subgroup, i.e. the Galilei group, are of diagonal form. The exact form of the unitary operator which connects the canonical basis of the P(1,4) group and the Galilei basis has been established.