Anderson impurity in a correlated conduction band

We investigate the physics of a magnetic impurity with spin 1/2 in a correl ated metallic host. Describing the band by a Hubbard Hamiltonian, the probl em is analyzed using dynamical mean-field theory in combination with Wilson 's nonperturbative numerical renormalization group. We present results for the single-particle density of states and the dynamical spin susceptibility at zero temperature. New spectral features (side peaks) are found which sh ould be observable experimentally. In addition, we find a general enhanceme nt of the Kondo scale due to correlations. Nevertheless, in the metallic ph ase, the Kondo scale always vanishes exponentially in the limit of small hy bridization.