Metal-insulator transition in the one-dimensional SU(N) Hubbard model

We investigate the metal-insulator transition of the one-dimensional SU(N) Hubbard model for repulsive interaction. Using the bosonization approach a Mott transition in the charge sector at half filling (k(F)=pi/Na-0) is conj ectured for N>2. Expressions for the charge and spin velocities as well as for the Luttinger-liquid parameters and some correlation functions are give n. The theoretical predictions are compared with numerical results obtained with an improved zero-temperature quantum Monte Carlo approach. The method used is a generalized Green's function Monte Carlo scheme in which the sto chastic time evolution is partially integrated out. Very accurate results f or the gaps, velocities, and Luttinger-liquid parameters as a function of t he Coulomb interaction U are given for the cases N=3 and N=4. Our results s trongly support the existence of a Mott-Hubbard transition at a nonzero val ue of the Coulomb interaction. We find U(c)similar to 2.2 for N=3 and U(c)s imilar to 2.8 for N=4.