English

On compactifications and product-free sets

Group Theory 2019-07-31 v2 Combinatorics Logic

Abstract

A subset of a group is said to be product-free if it does not contain three elements satisfying the equation xy=zxy=z. We give a negative answer to a question of Babai and S\'os on the existence of large product-free sets by model theoretic means. This question was originally answered by Gowers. Furthermore, we give a natural and sufficient model theoretic condition for a group to have a large product-free subset, as well as a model theoretic account of a result of Nikolov and Pyber on triple products.

Keywords

Cite

@article{arxiv.1807.10113,
  title  = {On compactifications and product-free sets},
  author = {Daniel Palacín},
  journal= {arXiv preprint arXiv:1807.10113},
  year   = {2019}
}
R2 v1 2026-06-23T03:15:22.088Z