A Remark on the Singularities of Solutions for Three-dimensional Nonlinear Wave Equations

Synopsis As a remark on [1], it is pointed out that Csolutions of u-sum from to n=1 to 3(u)=uwith compact supported initial data must vanish everywhere in R. A remark on Fritz John＇s paper [1] is given in this paper. In[2],a remarkable result is obtained that the Cauchy problem for nonlinear wave euation with small initial data always has global solution if the space dimension≥6.For the on-dimensional wave equation,the situation is just the