Critical behaviour near the metal-insulator transition of a doped Mott insulator

We have studied the critical behaviour of a doped Mott insulator near the m etal-insulator transition for the infinite-dimensional Hubbard model using a linearized form of dynamical mean-field theory. The discontinuity in the chemical potential in the change from hole to electron doping. for U larger than a critical value U-c, has been calculated analytically and is found t o be in good agreement with the results of numerical methods. We have also derived analytic expressions for the compressibility, the quasiparticle wei ght. the double occupancy and the local spin susceptibility near half-filli ng as functions of the on-site Coulomb interaction and the doping.