Critical norm blow-up for the energy supercritical nonlinear heat equation

Abstract

We address the critical norm blow-up problem for the nonlinear heat equation $u_t-\Delta u=|u|^{p-1}u$ in $\mathbf{R}^n\times(0,T)$. In the supercritical range $p>(n+2)/(n-2)$, we prove that if the maximal existence time $T$ is finite, then $\lim_{t\to T}\|u(\cdot,t)\|_{L^{n(p-1)/2}(\mathbf{R}^n)} =\infty$ without assuming extra conditions such as radial symmetry or the type of blow-up.