English

Hamilton cycles in tough $(2P_2 \cup P_1)$-free graphs

Combinatorics 2025-06-17 v1

Abstract

In 1973, Chv\'atal conjectured that there exists a constant t0t_0 such that every t0t_0-tough graph on at least three vertices is Hamiltonian. While this conjecture is still open, work has been done to confirm it for several graph classes, including all FF-free graphs for every 5-vertex linear forest FF other than P5P_5 and 2P2P12P_2\cup P_1. In this note, we show that 11-tough (2P2P1)(2P_2 \cup P_1)-free graphs on at least three vertices are Hamiltonian.

Keywords

Cite

@article{arxiv.2506.12684,
  title  = {Hamilton cycles in tough $(2P_2 \cup P_1)$-free graphs},
  author = {Songling Shan and Arthur Tanyel},
  journal= {arXiv preprint arXiv:2506.12684},
  year   = {2025}
}