Display Abstract

Title On quasilinear fractional PDEs and their local limits. Viscosity solution theory.

Name Espen R Jakobsen
Country Norway
Email erj@math.ntnu.no
Co-Author(s) Emmanuel Chasseigne
Submit Time 2014-02-17 08:49:55
Session
Special Session 76: Viscosity, nonlinearity and maximum principle
Contents
We introduce a class of fully non-linear quasilinear nonlocal equations of the form \begin{equation}F\big(x,u,Du,L[u,Du]\big)=0\tag{1}\end{equation} in whole space where $L$ is a nonlocal quasilinear Levy type operator. We show well-posedness of bounded viscosity solutions under assumptions that for the first time includes i) a gradient-dendence in $L$ and ii) cover the generators of SDEs driven by general pure jump Levy process. Next we study limit problems where the non-local operators converge to local ones: $$L_\epsilon[u,Du]\to \mathrm{tr}\big(\sigma(x,Du))\sigma(x,Du)D^2u\big) $$ as $\epsilon\to 0$. We prove that the solution $u_\epsilon$ of the $(1)$ with $L=L_\epsilon$ converges locally uniformly to the solution of the local problem \begin{equation*} F\Big(x,u,Du,\mathrm{tr}\big(\sigma(x,Du)\sigma(x,Du)D^2u\big)\Big)=0\qquad\text{in}\qquad \mathbb{R}^N. \end{equation*} We identify general conditions for this convergence, and are able to obtain in the local limit essentially any non-singular gradient-depending quasi-linear equation. Finally, we present non-local $p$-Laplace, infinity-Laplace and mean curvature of graph operators.