Abstract:
We establish conditions sufficient for the absence of global solutions of semilinear hyperbolic inequalities and systems in conic domains of the Euclidean space $\mathbb R^N$.
We consider a model problem in a cone $K$: that given by the inequality
$$
\dfrac{\partial^2u}{\partial t^2}-\Delta u\geqslant |u|^q, \qquad (x,t)\in K\times(0,\infty),
$$
The proof is based on the test-function method developed by Veron, Mitidieri, Pokhozhaev, and Tesei.