A HIDDEN SYMMETRY IN AN EXCITED-STATE OF THE ONE-DIMENSIONAL HUBBARD-MODEL

A symmetry property that holds between a certain subset of variables d escribing the Lieb-Wu solution of the one-dimensional Hubbard model is shown to be preserved under a transformation which allows one to desc ribe an excited state of the model which has a spin excitation. Numeri cal results for these variables which support the hypothesis are also presented for several values of the number of sites N. Some series exp ansions for the relevant variables as a function of the coupling are a lso presented. (C) 1998 Elsevier Science B.V.