文摘
Consider the diffusive Hamilton-Jacobi equation u t = Δu + |∇u| p , p > 2, on a bounded domain Ω with zero-Dirichlet boundary conditions, which arises in the KPZ model of growing interfaces. It is known that u remains bounded and that ∇u may blow up only on the boundary ∂Ω. In this paper, under suitable assumptions on W ¨¬ \mathbbR2{\Omega\subset \mathbb{R}^2} and on the initial data, we show that the gradient blow-up singularity occurs only at a single point x0 ? ?W{x_0\in\partial\Omega}. This is the first result of this kind in the study of problems involving gradient blow-up phenomena. In general domains of \mathbbRn{\mathbb{R}^n}, we also obtain results on nondegeneracy and localization of blow-up points.