ABSTRACT
A tensor operator is a set of operators that transforms under commutation with the generators of some Lie algebra like an irreducible representation of the algebra. This chapter defines and discusses tensor operators for the SU(2) algebra. A tensor operator transforming under the spin-s representation of SU(2) consists of a set of operators. The chapter shows the differences between dealing with states and dealing with tensor operators. The coefficients are entirely determined by the algebra, up to some choices of the phases of the states. The Clebsch-Gordan coefficients are all group theory. One of the reasons that tensor operators are important is that a product of two tensor operators.
