The blow-up rate for a non-scaling invariant semilinear wave equations

Blow up for the Semilinear Wave Equation in Schwarzschild Metric

We study the semilinear wave equation in Schwarzschild metric (3 + 1 dimensional space time). First, we establish that the problem is locally well posed in H for any σ > 1; then we prove the blow up of the solution for every p > 1 and non negative initial data. The work is dedicated to prof. Yvonne Choquet Bruhat in occasion of her 80th year.

Blow-up at the Boundary for Degenerate Semilinear Parabolic Equations

This paper concerns a superlinear parabolic equation, degenerate in the time derivative. It is shown that the solution may blow up in finite time. Moreover it is proved that for a large class of initial data blow-up occurs at the boundary of the domain when the nonlinearity is no worse than quadratic. Various estimates are obtained which determine the asymptotic behaviour near the blow-up. The ...

Blow-up Estimates for Higher-order Semilinear Parabolic Equations

On Blow-up at Space Infinity for Semilinear Heat Equations

We are interested in solutions of semilinear heat equations which blow up at space infinity. In [7], we considered a nonnegative blowing up solution of ut = ∆u+ u, x ∈ R, t > 0 with initial data u0 satisfying 0 ≤ u0(x) ≤ M, u0 ≡ M and lim |x|→∞0 = M, where p > 1 and M > 0 is a constant. We proved in [7] that the solution u blows up exactly at the blow-up time for the spatially constant solution...

Global solutions and finite time blow up for damped semilinear wave equations

A class of damped wave equations with superlinear source term is considered. It is shown that every global solution is uniformly bounded in the natural phase space. Global existence of solutions with initial data in the potential well is obtained. Finally, not only finite time blow up for solutions starting in the unstable set is proved, but also high energy initial data for which the solution ...