English

Monochromatic non-commuting products

Combinatorics 2024-05-08 v1 Dynamical Systems Number Theory

Abstract

We show that a finite coloring of an amenable group contains `many' monochromatic sets of the form {x,y,xy,yx},\{x,y,xy,yx\}, and natural extensions with more variables. This gives the first combinatorial proof and extensions of Bergelson and McCutcheon's non-commutative Schur theorem. Our main new tool is the introduction of what we call `quasirandom colorings,' a condition that is automatically satisfied by colorings of quasirandom groups, and a reduction to this case.

Keywords

Cite

@article{arxiv.2405.03772,
  title  = {Monochromatic non-commuting products},
  author = {Matt Bowen},
  journal= {arXiv preprint arXiv:2405.03772},
  year   = {2024}
}

Comments

18 pages, comments welcome

R2 v1 2026-06-28T16:18:34.892Z