English

On the Structure of Sets of Large Doubling

Classical Analysis and ODEs 2011-03-01 v4 Combinatorics

Abstract

We investigate the structure of finite sets AZA \subseteq \Z where A+A|A+A| is large. We present a combinatorial construction that serves as a counterexample to natural conjectures in the pursuit of an "anti-Freiman" theory in additive combinatorics. In particular, we answer a question along these lines posed by O'Bryant. Our construction also answers several questions about the nature of finite unions of B2[g]B_2[g] and B2[g]B^\circ_2[g] sets, and enables us to construct a Λ(4)\Lambda(4) set which does not contain large B2[g]B_2[g] or B2[g]B^\circ_2[g] sets.

Keywords

Cite

@article{arxiv.1003.4561,
  title  = {On the Structure of Sets of Large Doubling},
  author = {Allison Lewko and Mark Lewko},
  journal= {arXiv preprint arXiv:1003.4561},
  year   = {2011}
}

Comments

23 pages, changed title, revised version reflects work of Meyer that we were previously unaware of