Chvátal-Erdös type theorems
Discussiones Mathematicae. Graph Theory, Tome 30 (2010) no. 2, pp. 245-256
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The Chvátal-Erdös theorems imply that if G is a graph of order n ≥ 3 with κ(G) ≥ α(G), then G is hamiltonian, and if κ(G) > α(G), then G is hamiltonian-connected. We generalize these results by replacing the connectivity and independence number conditions with a weaker minimum degree and independence number condition in the presence of sufficient connectivity. More specifically, it is noted that if G is a graph of order n and k ≥ 2 is a positive integer such that κ(G) ≥ k, δ(G) > (n+k²-k)/(k+1), and δ(G) ≥ α(G)+k-2, then G is hamiltonian. It is shown that if G is a graph of order n and k ≥ 3 is a positive integer such that κ(G) ≥ 4k²+1, δ(G) > (n+k²-2k)/k, and δ(G) ≥ α(G)+k-2, then G is hamiltonian-connected. This result supports the conjecture that if G is a graph of order n and k ≥ 3 is a positive integer such that κ(G) ≥ k, δ(G) > (n+k²-2k)/k, and δ(G) ≥ α(G)+k-2, then G is hamiltonian-connected, and the conjecture is verified for k = 3 and 4.
Keywords:
Hamiltonian, Hamiltonian-connected, Chvátal-Erdös condition, independence number
@article{DMGT_2010_30_2_a4,
author = {Faudree, Jill and Faudree, Ralph and Gould, Ronald and Jacobson, Michael and Magnant, Colton},
title = {Chv\'atal-Erd\"os type theorems},
journal = {Discussiones Mathematicae. Graph Theory},
pages = {245--256},
year = {2010},
volume = {30},
number = {2},
language = {en},
url = {http://geodesic.mathdoc.fr/item/DMGT_2010_30_2_a4/}
}
TY - JOUR AU - Faudree, Jill AU - Faudree, Ralph AU - Gould, Ronald AU - Jacobson, Michael AU - Magnant, Colton TI - Chvátal-Erdös type theorems JO - Discussiones Mathematicae. Graph Theory PY - 2010 SP - 245 EP - 256 VL - 30 IS - 2 UR - http://geodesic.mathdoc.fr/item/DMGT_2010_30_2_a4/ LA - en ID - DMGT_2010_30_2_a4 ER -
Faudree, Jill; Faudree, Ralph; Gould, Ronald; Jacobson, Michael; Magnant, Colton. Chvátal-Erdös type theorems. Discussiones Mathematicae. Graph Theory, Tome 30 (2010) no. 2, pp. 245-256. http://geodesic.mathdoc.fr/item/DMGT_2010_30_2_a4/
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