English

A Cauchy-Davenport type result for arbitrary regular graphs

Combinatorics 2009-10-25 v2 Number Theory

Abstract

Motivated by the Cauchy-Davenport theorem for sumsets, and its interpretation in terms of Cayley graphs, we prove the following main result : There is a universal constant e > 0 such that, if G is a connected, regular graph on n vertices, then either every pair of vertices can be connected by a path of length at most 3, or the number of pairs of such vertices is at least 1+e times the number of edges in G. We discuss a range of further questions to which this result gives rise.

Keywords

Cite

@article{arxiv.0910.2250,
  title  = {A Cauchy-Davenport type result for arbitrary regular graphs},
  author = {Peter Hegarty},
  journal= {arXiv preprint arXiv:0910.2250},
  year   = {2009}
}

Comments

7 pages. Version 2 : typos corrected, acknowledgements added. This version has been submitted for publication

R2 v1 2026-06-21T13:57:27.499Z