Multiplicities in the Classical Groups. II

Abstract

In a previous paper, a method has been developed which allows a calculation in the same manner of all multiplicities occurring in the theory of linear representations of the classical compact Lie groups. This method is applied to the group SO(9) and some of its subgroups which are of interest in physics. It is demonstrated with the group SO(9) as example that this method of calculating the multiplicities allows us to accumulate in a condensed way a large amount of information and, moreover, that this method can be easily applied to any other (classical, compact) rank‐4 group and its semisimple subgroups.