In this paper, we give the following result: Let G be a 2-connected graph of order PZ> 13 and nd2az -3, where 02 = min{d(u) + d(u): uz'.$E(G)}. If the set of claw-centers of G is independent, then either G is hamiltonian or G belongs to three classes of exceptional graphs. The bound n <202 -3 is sha
Hamiltonicity in 2-connected graphs with claws
✍ Scribed by Hao Li; Mei Lu; Zhiren Sun
- Publisher
- Elsevier Science
- Year
- 1998
- Tongue
- English
- Weight
- 562 KB
- Volume
- 183
- Category
- Article
- ISSN
- 0012-365X
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✦ Synopsis
Matthews and Sumner have proved in [12] that if G is a 2-connected claw-free graph of order n such that 6>~(n-2)/3, then G is hamiltonian. Li has shown that the bound for the minimum degree 6 can be reduced to n/4 under the additional condition that G is not in /7, where /7 is a class of graphs defined in [7]. On the other hand, we say that a graph G is almost claw-free if the centres of induced claws are independent and their neighbourhoods are 2-dominated. Broersma, Ryjfirek and Schiermeyer have proved that if G is 2-connected almost claw-free graph of order n such that 6 >~(n -2)/3, then G is hamiltonian. We generalize these results by considering the graphs whose claw centres are independent. If G is a 2-connected graph of order n and minimum degree 6 such that n ~< 46 -3 and if the set of claw centres of G is independent, then we show that either G is hamiltonian or G C F, where F is a class of graphs defined in the paper. The bound n<~46 -3 is sharp.
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