Calculus of Variations and Geometric Measure Theory

M. Caroccia - S. Ciani

Dimensional lower bounds for contact surfaces of Cheeger sets

created by caroccia on 13 May 2020
modified on 21 Sep 2021

[BibTeX]

Accepted Paper

Inserted: 13 may 2020
Last Updated: 21 sep 2021

Journal: JMPA
Year: 2021

Abstract:

We carry on an analysis of the size of the contact surface of a Cheeger set $E$ with the boundary of its ambient space $\Omega$. We show that this size is strongly related to the regularity of $\partial \Omega$ by providing bounds on the Hausdorff dimension of $\partial E\cap \partial\Omega$. In particular we show that, if $\partial \Omega$ has $C^{1,\alpha}$ regularity then $\mathcal{H}^{d-2+\alpha}(\partial E\cap \partial\Omega)>0$. This shows that a sufficient condition to ensure that $\mathcal{H}^{d-1}(\partial E\cap \partial \Omega)>0$ is that $\partial \Omega$ has $C^{1,1}$ regularity. Since the Hausdorff bounds can be inferred in dependence of the regularity of $\partial E$ as well, we obtain that $\Omega$ convex, which yields $\partial E\in C^{1,1}$, is also a sufficient condition. Finally, we construct examples showing that such bounds are optimal in dimension $d=2$.


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