English

On random compact sets, equidecomposition, and domains of expansion in R^3

Metric Geometry 2021-04-06 v1 Combinatorics Logic Probability

Abstract

We study random compact subsets of R^3 which can be described as "random Menger sponges". We use those random sets to construct a pair of compact sets A and B in R^3 which are of the same positive measure, such that A can be covered by finitely many translates of B, B can be covered by finitely many translates of A, and yet A and B are not equidecomposable. Furthermore, we construct the first example of a compact subset of R^3 of positive measure which is not a domain of expansion. This answers a question of Adrian Ioana.

Keywords

Cite

@article{arxiv.2104.01244,
  title  = {On random compact sets, equidecomposition, and domains of expansion in R^3},
  author = {Tomasz Cieśla and Łukasz Grabowski},
  journal= {arXiv preprint arXiv:2104.01244},
  year   = {2021}
}

Comments

15 pages