A complete set of basis vectors of the Anderson model and its Kondo dynamics

We study Kondo dynamics in the single-impurity Anderson model in terms of operator basis vectors. A complete set of basis vectors is determined by using the Hamiltonian of this model. Then, we construct a reduced Liouville space by eliminating some basis vectors that are unimportant in the Kondo regime, and we obtain the retarded Green's function. We compare our results with those of Fermi liquid theory and the numerical renormalization group method.