English

Graham conjecture on small sets in abelian groups

Number Theory 2026-03-24 v1 Combinatorics

Abstract

A famous conjecture of Graham asserts that every set AZp{0}A \subseteq \mathbb{Z}_p \setminus \{0\} can be ordered so that all partial sums are distinct. Although this conjecture was recently proved for sufficiently large primes by Pham and Sauermann in~\cite{PM} (combined with earlier results of \cite{BBKMM}), it remains open for general abelian groups, even in the cyclic case Zk\mathbb{Z}_k. In this paper, using a recursive approach, we investigate the sequenceability of subsets AA in generic abelian groups for small values of A|A|. We prove that any subset AG{0}A \subseteq G\setminus\{0\} with A20|A| \leq 20 is sequenceable where previously it was known only for A9|A|\leq 9. This bound is improved to A22|A| \leq 22 for zero-sum subsets. Finally, regarding the related CMPP conjecture, we show that zero-sum subsets without inverse pairs are sequenceable for A23|A| \leq 23.

Keywords

Cite

@article{arxiv.2603.20961,
  title  = {Graham conjecture on small sets in abelian groups},
  author = {Simone Costa and Stefano Della Fiore and Mattia Fontana and Lluís Vena},
  journal= {arXiv preprint arXiv:2603.20961},
  year   = {2026}
}
R2 v1 2026-07-01T11:31:44.705Z