We have decided to discontinue the publication of preprints on our preprint server as of 1 March 2024. The publication culture within mathematics has changed so much due to the rise of repositories such as ArXiV (www.arxiv.org) that we are encouraging all institute members to make their preprints available there. An institute's repository in its previous form is, therefore, unnecessary. The preprints published to date will remain available here, but we will not add any new preprints here.
MiS Preprint
6/2008
Some remarks on the strong maximum principle arising in nonlocal operators
Pascal Autissier and Jerome Coville
Abstract
In this note we make some remarks concerning maximum principles holding for nonlocal diffusion operator of the form $$\mathcal{M}[u](x) :=\int_{G}J(g)u(x*g^{-1})d\mu(g) - u(x),$$ where $G$ is a group acting continuously on a Hausdorff space $X$ and $u\in C(X)$.
We first investigate the existence of a strong maximum principle in the general situation and then focus on the case of homogeneous spaces. Depending on the topology of the homogenerous space, we give contidions on $J$ and $d\mu$ such that $\mathcal{M}$ achieves a strong maximum principle. We also revisit the classical case of convolution operator on $\mathbb{R}^n$.
