“…Most of them are results for blow up of solutions, see [29,25,16]. Similar analysis, for E 0 ≥ d, have been performed to prove the same qualitative properties for other equations, see [14,28] to cite just some of the most influential papers on the subject, and see [4,19,20,26,30,31,35,36,37] and references therein for some recent works. In [6] a numerical study for the Cauchy problem of the focusing cubic nonlinear Klein-Gordon equation in three dimensions for radial initial data shows that for high energies, the qualitative behavior seems to be much more complicated than for E < d, and more research is required to find a threshold between globality and blow up of solutions.…”