Trace techniques for angular momentum operators
P. R. Subramanian, Varadarajan Devanathan · Journal of Physics A Mathematical Nuclear and General · 1974
General expressions for traces of products of angular momentum matrices (both in Cartesian and spherical bases) for systems of arbitrary spin are derived using the well established properties. It is shown that the trace is a polynominal in eta where eta is the eigenvalue of the J 2 operator. The trace techniques developed herein are applied to the problems of spin orientation.