A Note on Fractional KdV Hierarchies
  We introduce a hierarchy of mutually commuting dynamical systems on a finite number of Laurent series. This hierarchy can be seen as a prolongation of the KP hierarchy, or a ``reduction'' in which the space coordinate is identified with an arbitrarily chosen time of a bigger dynamical system. Fractional KdV hierarchies are gotten by means of further reductions, obtained by constraining the Laurent series. The case of sl(3)^2 and its bihamiltonian structure are discussed in detail. 
Paolo Casati (Dip. di Matematica, Univ. di Milano, Italy), Gregorio   Falqui (SISSA, Trieste, Italy), Franco Magri (Dip. di ...