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More powerful closure operations on graphs

✍ Scribed by Yong-jin Zhu; Feng Tian; Xiao-tie Deng


Publisher
Elsevier Science
Year
1991
Tongue
English
Weight
1017 KB
Volume
87
Category
Article
ISSN
0012-365X

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✦ Synopsis


Zhu, Y.-J., F. Tian and X.-T. Deng, More powerful closure operations on graphs, Discrete Mathematics 87 (1991) 197-214. Bondy and Chvatal have observed the following result: G = (V, E) is a simple graph of order n. If uu $ E and d(u) + d(u) 2 n, then G is Hamiltonian iff G + uu is Hamiltonian. Thus, we can obtain a graph C,(G), named the n-closure of G, from G by successively joining pairs of non-adjacent vertices whose degree sum is at least n. Therefore, G is Hamiltonian if C,(G) is Hamiltonian. Moreover, Bondy and Chvatal (21 generalized this idea to several properties on G. In the paper, we present some more powerful closure operations that extend the idea of Bondy and Chvatal.


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