abstract: This lecture is devoted to some results of wellposedness of the Cauchy problem for hyperbolic equations having non-Lipschitz continuous coefficients. In particular I will present a wellposednes theorem concerning the case of coefficients which are Log-Zygmund continuous with respect to the time variable and Log-Lipschitz continuous with respect to the space variables (joint work with F. Colombini, F. Fanelli and G. Métivier)
DelSanto