English

Arithmetical structure of sumset intersections

Number Theory 2026-03-17 v1

Abstract

The hh-fold sumset of a set AA of integers is the set of all sums of hh not necessarily distinct elements of AA. Let (Aq)q=1(A_q)_{q=1}^{\infty} be a strictly decreasing sequence of sets of integers and let A=q=1AqA = \bigcap_{q=1}^{\infty} A_q. Then hAq=1hAqhA \subseteq \bigcap_{q=1}^{\infty} hA_q for all h1h \geq 1. Let H(Aq)={h1:hA=q=1hAq}\mathcal{H}(A_q) = \{h \geq 1: hA = \bigcap_{q=1}^{\infty} hA_q\}. The arithmetical structure of the sets H(Aq)\mathcal{H}(A_q) is unknown. It is proved that for every h02h_0 \geq 2 there exist sequences (Aq)q=1(A_q)_{q=1}^{\infty} such that {1,,h01}H(Aq)\{1,\ldots, h_0-1\} \subseteq \mathcal{H}(A_q) but h0H(Aq)h_0 \notin \mathcal{H}(A_q) and also that there exist sequences (Aq)q=1(A_q)_{q=1}^{\infty} such that {1,h0}H(Aq)\{1, h_0 \} \subseteq \mathcal{H}(A_q) but {2,3,,h01}H(Aq)=\{2,3, \ldots, h_0-1\} \cap \mathcal{H}(A_q) = \emptyset.

Keywords

Cite

@article{arxiv.2603.14510,
  title  = {Arithmetical structure of sumset intersections},
  author = {Diego Marques and Melvyn B. Nathanson},
  journal= {arXiv preprint arXiv:2603.14510},
  year   = {2026}
}

Comments

7 pages

R2 v1 2026-07-01T11:20:54.911Z