On s-hamiltonian line graphs of claw-free graphs

Autor: Hong-Jian Lai, Mingquan Zhan, Taoye Zhang, Ju Zhou
Rok vydání: 2019
Předmět:
Zdroj: Discrete Mathematics. 342:3006-3016
ISSN: 0012-365X
DOI: 10.1016/j.disc.2019.06.006
Popis: For an integer s ≥ 0 , a graph G is s -hamiltonian if for any vertex subset S ⊆ V ( G ) with | S | ≤ s , G − S is hamiltonian, and G is s -hamiltonian connected if for any vertex subset S ⊆ V ( G ) with | S | ≤ s , G − S is hamiltonian connected. Thomassen in 1984 conjectured that every 4-connected line graph is hamiltonian (see Thomassen, 1986), and Kuczel and Xiong in 2004 conjectured that every 4-connected line graph is hamiltonian connected (see Ryjacek and Vrana, 2011). In Broersma and Veldman (1987), Broersma and Veldman raised the characterization problem of s -hamiltonian line graphs. In Lai and Shao (2013), it is conjectured that for s ≥ 2 , a line graph L ( G ) is s -hamiltonian if and only if L ( G ) is ( s + 2 ) -connected. In this paper we prove the following. (i) For an integer s ≥ 2 , the line graph L ( G ) of a claw-free graph G is s -hamiltonian if and only if L ( G ) is ( s + 2 ) -connected. (ii) The line graph L ( G ) of a claw-free graph G is 1-hamiltonian connected if and only if L ( G ) is 4-connected.
Databáze: OpenAIRE