Published online by Cambridge University Press: 09 April 2009
It is well known that a wide range of Special Function Theory can be realized by considering unitary representations of certain topological groups.
In this approach it is very important to determine all irreducible continuous unitary representations of the group in question.
For the group of movements this problem was initiated by Vilenkin [6]. Rather restrictive conditions were imposed in this paper and while he returned to the problem in [7], it was still not solved in full generality (among other things the representation space was assumed separable). The first complete solution appears to have been given by Thoma [5]. Here, the method was to show each irreducible continuous unitary representation equivalent to a particular representation in a space of square integrable functions.