2016/09/26 by Hynd, Ryan, Lindgren, Erik · 1 citation
#Analysis of PDEs (math.AP) #FOS: Mathematics
paper · doi:10.48550/arxiv.1609.08186
For a bounded domain Ω⊂ ℝn and p>n, Morrey's inequality implies that there is c>0 such that c‖u‖p∞≤ ∫Ω|Du|pdx for each u belonging to the Sobolev space W1,p0(Ω). We show that the ratio of any two extremal functions is constant provided that Ω is convex. We also explain why this property fails to hold in general and verify that convexity is not a necessary condition for a domain to have this property. As a by product, we obtain the uniqueness of an optimization problem involving the Green's function for the p-Laplacian.