Abstract:
The Cauchy problem for a model nonlinear equation with gradient nonlinearity is considered. We prove the existence of two critical exponents, $q_1=2$ and $q_2=3$, such that this problem has no local-in-time weak (in some sense) solution for $1<q\le q_1$, while such a solution exists for $q>q_1$, but, for $q_1<q\le q_2$, there is no global-in-time weak solution.
Key words:nonlinear Sobolev-type equations, blow-up, local solvability, nonlinear capacity, blow-up time estimates.