On Sets Containing an Affine Copy of Bounded Decreasing Sequences

Tongou Yang

Published 2019-01-18Version 1

How small can a set be while containing many configurations? Following up on earlier work of Erd\"os and Kakutani \cite{MR0089886}, Math\'e \cite{MR2822418} and M\"olter and Yavicoli \cite{Molter}, we address the question in two directions. On one hand, if a subset of the real numbers contains an affine copy of all bounded decreasing sequences, then we show that such subset must be somewhere dense. On the other hand, given a collection of convergent sequences with prescribed decay, there is a closed and nowhere dense subset of the reals that contains an affine copy of every sequence in that collection.