English

Accessible parts of the boundary for domains with lower content regular complements

Metric Geometry 2019-02-20 v2 Analysis of PDEs Classical Analysis and ODEs

Abstract

We show that if 0<t<sn10<t<s\leq n-1, ΩRn\Omega\subseteq \mathbb{R}^{n} with lower ss-content regular complement, and zΩz\in \Omega, there is a chord-arc domain ΩzΩ\Omega_{z}\subseteq \Omega with center zz so that Ht(ΩzΩ)tdist(z,Ωc)t\mathscr{H}^{t}_{\infty}(\partial\Omega_{z}\cap \partial\Omega)\gtrsim_{t} \textrm{dist}(z,\Omega^{c})^{t}. This was originally shown by Koskela, Nandi, and Nicolau with John domains in place of chord-arc domains when n=2n=2, s=1s=1, and Ω\Omega is a simply connected planar domain. Domains satisfying the conclusion of this result support (p,β)(p,\beta)-Hardy inequalities for β<pn+t\beta<p-n+t by a result of Koskela and Lehrb\"{a}ck; Lehrb\"{a}ck also showed that ss-content regularity of the complement for some s>np+βs>n-p+\beta was necessary. Thus, the combination of these results gives a characterization of which domains support pointwise (p,β)(p,\beta)-Hardy inequalities for β<p1\beta<p-1 in terms of lower content regularity.

Keywords

Cite

@article{arxiv.1807.04534,
  title  = {Accessible parts of the boundary for domains with lower content regular complements},
  author = {Jonas Azzam},
  journal= {arXiv preprint arXiv:1807.04534},
  year   = {2019}
}

Comments

Corrected typos, added some more detail. To appear in Annales Academi{\ae} Scientiarum Fennic{\ae}