Separating topological recurrence from measurable recurrence: exposition and extension of Kriz's example

Abstract

We prove that for every infinite set $E\subset \mathbb Z$, there is a set $S\subset E-E$ which is a set of topological recurrence and not a set of measurable recurrence. This extends a result of Igor Kriz, proving that there is a set of topological recurrence which is not a set of measurable recurrence. Our construction follows Kriz's closely, and this paper can be considered an exposition of the original argument.