Let G be a graph. Adopting the terminology of Broersma et al. and Čada, respectively, we say that G is 2-heavy if every induced claw (K1,3) of G contains two end-vertices each one has degree at least |V (G)|/2; and G is o-heavy if every induced claw of G contains two end-vertices with degree sum at least |V (G)| in G. In this paper, we introduce a new concept, and say that G is S-c-heavy if for a given graph S and every induced subgraph G′ of G isomorphic to S and every maximal clique C of G′, every non-trivial component of G′ − C contains a vertex of degree at least |V (G)|/2 in G. Our original motivation is a theorem of Hu from 1999 that can be stated, in terms of this concept, as every 2-connected 2-heavy and N-c-heavy graph is hamiltonian, where N is the graph obtained from a triangle by adding three disjoint pendant edges. In this paper, we will characterize all connected graphs S such that every 2-connected o-heavy and S-c-heavy graph is hamiltonian. Our work results in a different proof of a stronger version of Hu’s theorem. Furthermore, our main result improves or extends several previous results.
@article{bwmeta1.element.doi-10_7151_dmgt_1967,
author = {Binlong Li and Bo Ning},
title = {Heavy Subgraphs, Stability and Hamiltonicity},
journal = {Discussiones Mathematicae Graph Theory},
volume = {37},
year = {2017},
pages = {691-710},
language = {en},
url = {http://dml.mathdoc.fr/item/bwmeta1.element.doi-10_7151_dmgt_1967}
}
Binlong Li; Bo Ning. Heavy Subgraphs, Stability and Hamiltonicity. Discussiones Mathematicae Graph Theory, Tome 37 (2017) pp. 691-710. http://gdmltest.u-ga.fr/item/bwmeta1.element.doi-10_7151_dmgt_1967/