The Completion of a Classification for Maximal Nonhamiltonian Burkard–Hammer Graphs
- 47 Downloads
Abstract
A graph G=(V,E) is called a split graph if there exists a partition V=I∪K such that the subgraphs G[I] and G[K] of G induced by I and K are empty and complete graphs, respectively. Burkard and Hammer gave a necessary condition for a split graph G with |I|<|K| to be Hamiltonian (J. Comb. Theory, Ser. B 28:245–248, 1980). We will call a split graph G with |I|<|K| satisfying this condition a Burkard–Hammer graph. Further, a split graph G is called a maximal nonhamiltonian split graph if G is nonhamiltonian but G+uv is Hamiltonian for every \(uv\not\in E\), where u∈I and v∈K. N.D. Tan and L.X. Hung have classified maximal nonhamiltonian Burkard–Hammer graphs G with minimum degree δ(G)≥|I|−3. Recently, N.D. Tan and Iamjaroen have classified maximal nonhamiltonian Burkard–Hammer graphs with |I|≠6,7 and δ(G)=|I|−4. In this paper, we complete the classification of maximal nonhamiltonian Burkard–Hammer graphs with δ(G)=|I|−4 by finding all such graphs for the case |I|=6,7.
Keywords
Split graph Burkard–Hammer condition Burkard–Hammer graph Hamiltonian graph Maximal nonhamiltonian split graphMathematics Subject Classification (2000)
05C45 05C75Notes
Acknowledgements
I would like to express my sincere thanks to the referee for his valuable remarks which helped me to improve the paper.
References
- 1.Behzad, M., Chartrand, G.: Introduction to the Theory of Graphs. Allyn & Bacon, Boston (1971) MATHGoogle Scholar
- 2.Burkard, R.E., Hammer, P.L.: A note on Hamiltonian split graphs. J. Comb. Theory, Ser. B 28, 245–248 (1980) CrossRefMATHMathSciNetGoogle Scholar
- 3.Chvátal, V., Hammer, P.L.: Aggregation of inequalities in integer programming. Ann. Discrete Math. 1, 145–162 (1977) CrossRefGoogle Scholar
- 4.Földes, S., Hammer, P.L.: Split graphs. In: Proceedings of the Eighth Southeastern Conference on Combinatorics, Graph Theory and Computing, Louisiana State Univ., Baton Rouge, LA, 1977. Congressus Numerantium, vol. XIX, pp. 311–315. Utilitas Math., Winnipeg (1977) Google Scholar
- 5.Földes, S., Hammer, P.L.: On a class of matroid-producing graphs. In: Combinatorics, Proc. Fifth Hungarian Colloq., Keszthely, 1976. Colloq. Math. Soc. Janós Bolyai 18, vol. 1, pp. 331–352. North-Holland, Amsterdam (1978) Google Scholar
- 6.Henderson, P.B., Zalcstein, Y.: A graph-theoretic characterization of the PV chunk class of synchronizing primitive. SIAM J. Comput. 6, 88–108 (1977) CrossRefMATHMathSciNetGoogle Scholar
- 7.Hesham, A.H., Hesham, El.R.: Task allocation in distributed systems: a split graph model. J. Comb. Math. Comb. Comput. 14, 15–32 (1993) MATHGoogle Scholar
- 8.Kratsch, D., Lehel, J., Müller, H.: Toughness, Hamiltonicity and split graphs. Discrete Math. 150, 231–245 (1996) CrossRefMATHMathSciNetGoogle Scholar
- 9.Peemöller, J.: Necessary conditions for Hamiltonian split graphs. Discrete Math. 54, 39–47 (1985) MATHMathSciNetGoogle Scholar
- 10.Peled, U.N.: Regular Boolean functions and their polytope. Chap. VI, Ph.D. Thesis, Univ. Waterloo, Dept. Comb. Optim. (1975) Google Scholar
- 11.Tan, N.D.: A note on maximal nonhamiltonian Burkard–Hammer graphs. Vietnam J. Math. 34, 397–409 (2006) MATHMathSciNetGoogle Scholar
- 12.Tan, N.D., Hung, L.X.: Hamilton cycles in split graphs with large minimum degree. Discuss. Math. Graph Theory 24, 23–40 (2004) CrossRefMATHMathSciNetGoogle Scholar
- 13.Tan, N.D., Hung, L.X.: On the Burkard–Hammer condition for Hamiltonian split graphs. Discrete Math. 296, 59–72 (2005) CrossRefMATHMathSciNetGoogle Scholar
- 14.Tan, N.D., Iamjaroen, C.: Constructions for nonhamiltonian Burkard–Hammer graphs. In: Combinatorial Geometry and Graph Theory (Proc. of Indonesia–Japan Joint Conf.), Bandung, Indonesia, September 13–16, 2003. Lect. Notes Comput. Sci., vol. 3330, pp. 185–199. Springer, Berlin (2005) CrossRefGoogle Scholar
- 15.Tan, N.D., Iamjaroen, C.: A necessary condition for maximal nonhamiltonian Burkard–Hammer graphs. J. Discrete Math. Sci. Cryptogr. 9, 235–252 (2006) CrossRefMATHMathSciNetGoogle Scholar
- 16.Tan, N.D., Iamjaroen, C.: A classification for maximal nonhamiltonian Burkard–Hammer graphs. Discuss. Math. Graph Theory 28, 67–89 (2008) CrossRefMATHMathSciNetGoogle Scholar