English

On weak Sierpi\'nski sets in groups and free subgroups

Group Theory 2019-03-21 v3

Abstract

In this paper we discuss the problem of existence of so called weak Sierpi\'nski sets in groups. It is known that group GG has a Sierpi\'nski subset if and only if it contains a free subgroup. In their paper, Tomkowicz and Wagon conjectured that an analogous result holds also for the weaker condition. We derive a number of properties of groups with weak Sierpi\'nski subsets and use them to prove the above mentioned conjecture. This is an improved version of arXiv:1805.11486. Some of the included proofs have been simplified and shortened.

Keywords

Cite

@article{arxiv.1805.11486,
  title  = {On weak Sierpi\'nski sets in groups and free subgroups},
  author = {Agnieszka Bier and Piotr Słanina},
  journal= {arXiv preprint arXiv:1805.11486},
  year   = {2019}
}

Comments

The results elaborated in this paper have been improved and complemented in another work arXiv:1903.07043

R2 v1 2026-06-23T02:12:02.742Z