English

Hamilton Cycles in Semisymmetric Graphs

Combinatorics 2026-02-17 v1

Abstract

In light of Lov\'{a}sz's longstanding question on the existence of Hamilton paths in vertex-transitive graphs, this paper considers a natural variant: what if vertex-transitivity is relaxed, yet a high degree of symmetry--specifically edge-transitivity--is retained? To investigate this, we focus on the class of semisymmetric graphs, which are regular, edge-transitive, but not vertex-transitive. In this paper, it will be shown that every connected semisymmetric graph of order 2pq2pq, where pp and qq are two distinct primes contains a Hamilton cycle and that every connected cubic semisymmetric graph of order less than 3000 contains a Hamilton cycle too. Based on these observations, the following question is posed: construct a connected semisymmetric graph which has no Hamilton cycle.

Keywords

Cite

@article{arxiv.2602.14388,
  title  = {Hamilton Cycles in Semisymmetric Graphs},
  author = {Shaofei Du and Kai Yuan},
  journal= {arXiv preprint arXiv:2602.14388},
  year   = {2026}
}
R2 v1 2026-07-01T10:37:53.950Z