English

Rado equations solved by linear combinations of idempotent ultrafilters

Combinatorics 2021-11-04 v3 Logic

Abstract

We fully characterise the solvability of Rado equations inside linear combinations a1\Uan\Ua_{1}\U\oplus\dots\oplus a_{n}\U of idempotent ultrafilters \UβZ\U\in\beta\Z by exploiting known relations between such combinations and strings of integers. This generalises a partial characterization previously obtained by Mauro Di Nasso.

Keywords

Cite

@article{arxiv.2011.13722,
  title  = {Rado equations solved by linear combinations of idempotent ultrafilters},
  author = {Lorenzo Luperi Baglini and Paulo Henrique Arruda},
  journal= {arXiv preprint arXiv:2011.13722},
  year   = {2021}
}