CONSTRAINT QUANTIZATION OF SLAVE-PARTICLE THEORIES

We start from the Barnes-Coleman slave-particle description, where the Hubbard operators X are decomposed into a product of fermionic (f(alp ha)) and bosonic (b) operators. The quantum mechanical constraint b(+) b + Sigma(alpha)f(alpha)dagger f(alpha) = 1 is treated within the fram ework of Dirac's method for the quantization of classical constrained systems. This leads to modified algebraic properties of the fundamenta l operators: bb dagger b = b, f(alpha)f(beta)dagger f(gamma) = delta(a lpha beta)f(gamma) and f alpha b dagger = 0. Thereby the algebra of th e X-operators is preserved exactly on the operator level. Matrix repre sentations of the above algebra are constructed and a resolvent-like p erturbation theory for the single-impurity Anderson model is developed .