SPECTRAL-FUNCTION AND SELF-ENERGY OF THE ONE-DIMENSIONAL HUBBARD-MODEL IN THE U-]INFINITY LIMIT

The interpretation of the k dependent spectral functions of the one-di mensional, infinite U Hubbard model obtained by using the factorized w ave-function of Ogata and Shiba is revisited. The well defined feature which appears in addition to low energy features typical of Luttinger liquids, and which, close to the Fermi energy, dan be interpreted as the shadow band resulting from 2k(F) spin fluctuations, is further inv estigated. A calculation of the self-energy shows that, not too close to the Fermi energy, this feature corresponds to a band, i.e. to a sol ution of the Dyson equation omega - epsilon(k) - Re Sigma(k, omega) = 0.