“…As a simple example, consider a scalar field Z which is an N × N matrix transforming in the adjoint representation of U(N). A complete set of operators built using three fields is given by {Tr(Z It is a highly non-trivial problem to write a basis of local operators that is not over complete at finite N. This problem has been solved for multimatrix models with U(N) gauge group in [1,2,3,4,5,6,7,8,9] and for single matrix models with SO(N) or Sp(N) gauge groups in [10,11,12]. The result of these studies is a basis of local operators that also diagonalizes the free field two point function.…”