Hereditarily Non Uniformly Perfect Sets

Abstract

We introduce the concept of hereditarily non uniformly perfect sets, compact sets for which no compact subset is uniformly perfect, and compare them with the following: Hausdorff dimension zero sets, logarithmic capacity zero sets, Lebesgue 2-dimensional measure zero sets, and porous sets. In particular, we give an example of a compact set in the plane of Hausdorff dimension 2 (and positive logarithmic capacity) which is hereditarily non uniformly perfect.

14 pages. See also http://rstankewitz.iweb.bsu.edu/, http://sugawa.cajpn.org/index_E.html, http://www.math.sci.osaka-u.ac.jp/~sumi/