Hölder stability for Serrin's overdetermined problem
Year: 2014
Type: preprint
Abstract: In a bounded domain $Ω$, we consider a positive solution of the problem $Δu+f(u)=0$ in $Ω$, $u=0$ on $\partialΩ$, where $f:\mathbb{R}\to\mathbb{R}$ is a locally Lipschitz continuous function. Under sufficient conditions on $Ω$ (for instance, if $Ω$ is convex), we show that $\partialΩ$ is contained in a spherical annulus of radii $r_i0$ and $α\in (0,1]$. Here, $[u_ν]_{\partialΩ}$ is the Lipschitz seminorm on $\partialΩ$ of the normal derivative of $u$. This result improves to Hölder stability the logarithmic estimate obtained in [1] for Serrin's overdetermined problem. It also extends to a large class of semilinear equations the Hölder estimate obtained in [6] for the case of torsional rigidity ($f\equiv 1$) by means of integral identities. The proof hinges on ideas contained in [1] and uses Carleson-type estimates and improved Harnack inequalities in cones.
Source: arXiv (Cornell University)
Language: English
Subfield: Applied Mathematics
Field: Mathematics
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2951614464