Interior Regularity of Mixed Local-Nonlocal Parabolic Semilinear Equations

Abstract

In this paper we prove the existence, uniqueness and regularity of classical solutions \break of a semilinear parabolic equation with a mixed local and nonlocal diffusion operator \break $\mathcal{L} = -(-\Delta)^s + \Delta$ and Dirichlet boundary conditions. Here, $(-\Delta)^s$ is the integral fractional laplacian and $\Delta$ is the classic local laplacian. We then study the interior regularity of said solutions and conclude that they are H\"older continuous in both space and time, and they are $C^{2,\alpha}_{loc}$ in space for all positive times.