English

Approximation of a Reifenberg-flat set by a smooth surface

Classical Analysis and ODEs 2012-12-07 v2

Abstract

We show that if E\iRnE \i \R^n is a Reifenberg flat set EE of dimension dd at scale r0r_0, we can find a smooth surface Σ0\Sigma_0 of dimension dd which is close to EE at the scale r0r_0. When EE is a Reifenberg flat set, this allows us to apply a result of G. David and T. Toro [Memoirs of the AMS 215 (2012), 1012], and get a bi-H\"older homeomorphism of Rn\R^n that sends Σ0\Sigma_0 to EE. If in addition d=n1d=n-1 and EE is compact and connected, then Σ0\Sigma_0 is orientable, and Rn\smE\R^n \sm E has exactly two connected components, which we can approximate from the inside by smooth domains.

Keywords

Cite

@article{arxiv.1211.3222,
  title  = {Approximation of a Reifenberg-flat set by a smooth surface},
  author = {Guy David},
  journal= {arXiv preprint arXiv:1211.3222},
  year   = {2012}
}
R2 v1 2026-06-21T22:38:04.819Z