Monochromatic Sumsets in Countable Colourings of Abelian Groups
Combinatorics
2024-07-08 v1
Abstract
Fern\'andez-Bret\'on, Sarmiento and Vera showed that whenever a direct sum of sufficiently many copies of , the cyclic group of order 4, is countably coloured there are arbitrarily large finite sets whose sumsets are monochromatic. They asked if the elements of order 4 are necessary, in the following strong sense: if is an abelian group having no elements of order 4, is it always the case there there is a countable colouring of for which there is not even a monochromatic sumset with of size 2? Our aim in this short note is to show that this is indeed the case.
Cite
@article{arxiv.2407.03938,
title = {Monochromatic Sumsets in Countable Colourings of Abelian Groups},
author = {Imre Leader and Kada Williams},
journal= {arXiv preprint arXiv:2407.03938},
year = {2024}
}