Isolated Singularities of Nonlinear Polyharmonic Inequalities

Abstract

We obtain results for the following question where $m\ge 1$ and $n\ge 2$ are integers. {\bf Question.} For which continuous functions $f:[0,\infty )\to [0,\infty )$ does there exist a continuous function $\varphi :(0,1)\to (0,\infty )$ such that every $C^{2m}$ nonnegative solution $u(x)$ of 0 \le -Δ^m u\le f(u)\quad \text{in}\quad B_2(0)\backslash\{0\}\subset {\bb R}^n satisfies u(x) = O(ϕ(|x|))\quad \text{as}\quad x\to 0 and what is the optimal such $\varphi$ when one exists?

31 pages