Monochromatic Sums and Products over $\mathbb{Q}$

Abstract

Hindman's finite sums theorem states that in any finite coloring of the naturals, there is an infinite sequence so that all of its finite subset sums are the same color. In 1979, Hindman showed that there is a finite coloring of the naturals so that no infinite sequence has all of its pairwise sums and pairwise products the same color. Hindman conjectured that for any $n$, a finite coloring of the naturals contains $n$ numbers all of whose subset sums and subset products are the same color. In this paper we prove the version of this statement where we color the rationals instead of the integers. In other words, we show that the pattern $\{{\sum }_{i\in S}{x}_i,{\prod }_{i\in S}{x}_i\}$, where $S$ ranges over all nonempty subsets of $[n]$, is partition regular over the rationals.

v6, accepted in Duke Math Journal