NONCRITICAL LIGHT-CONE STRING

A free string quantum model is constructed directly in the light-cone variables in the range of dimensions 1 < D < 25. The longitudinal degr ees of freedom are described by an abstract Verma module with the cent ral charge restricted by the requirement of closure of the non-linear realization of the Poincare algebra. The spin content of the model is analyzed. In particular for D = 4 the explicit formulae for the charac ter generating functions of the open and closed strings are given and the spin spectrum of the first twelve excited levels is calculated. It is shown that for the space-time dimension in the range 1 < D < 25 th is light-cone quantum model is equivalent to the critical massive stri ng and to the non-critical Nambu-Goto string. (C) 1998 Elsevier Scienc e B.V.