English

Examples of non-Dini domains with large singular sets

Complex Variables 2022-12-06 v1 Analysis of PDEs Classical Analysis and ODEs

Abstract

Let uu be a non-trivial harmonic function in a domain DRdD\subset \mathbb{R}^d which vanishes on an open set of the boundary. In a recent paper, we showed that if DD is a C1C^1-Dini domain, then within the open set the singular set of uu, defined as {XD:u(X)=0=u(X)}\{X\in \overline{D}: u(X) = 0 = |\nabla u(X)|\} , has finite (d2)(d-2)-dimensional Hausdorff measure. In this paper, we show that the assumption of C1C^1-Dini domains is sharp, by constructing a large class of non-Dini (but almost Dini) domains whose \textit{singular sets} have infinite Hd2\mathcal{H}^{d-2}-measures.

Keywords

Cite

@article{arxiv.2212.01541,
  title  = {Examples of non-Dini domains with large singular sets},
  author = {Carlos Kenig and Zihui Zhao},
  journal= {arXiv preprint arXiv:2212.01541},
  year   = {2022}
}
R2 v1 2026-06-28T07:21:04.605Z