Title:
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The hamiltonian chromatic number of a connected graph without large hamiltonian-connected subgraphs (English) |
Author:
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Nebeský, Ladislav |
Language:
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English |
Journal:
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Czechoslovak Mathematical Journal |
ISSN:
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0011-4642 (print) |
ISSN:
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1572-9141 (online) |
Volume:
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56 |
Issue:
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2 |
Year:
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2006 |
Pages:
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317-338 |
Summary lang:
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English |
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Category:
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math |
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Summary:
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If $G$ is a connected graph of order $n \ge 1$, then by a hamiltonian coloring of $G$ we mean a mapping $c$ of $V(G)$ into the set of all positive integers such that $\vert c(x) - c(y)\vert \ge n - 1 - D_{G}(x, y)$ (where $D_{G}(x, y)$ denotes the length of a longest $x-y$ path in $G$) for all distinct $x, y \in V(G)$. Let $G$ be a connected graph. By the hamiltonian chromatic number of $G$ we mean \[ \min (\max (c(z);\, z \in V(G))), \] where the minimum is taken over all hamiltonian colorings $c$ of $G$. The main result of this paper can be formulated as follows: Let $G$ be a connected graph of order $n \ge 3$. Assume that there exists a subgraph $F$ of $G$ such that $F$ is a hamiltonian-connected graph of order $i$, where $2 \le i \le \frac{1}{2}(n + 1)$. Then $\mathop {\mathrm hc}(G) \le (n - 2)^2 + 1 - 2(i - 1)(i - 2)$. (English) |
Keyword:
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connected graphs |
Keyword:
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hamiltonian-connected subgraphs |
Keyword:
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hamiltonian colorings |
Keyword:
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hamiltonian chromatic number |
MSC:
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05C15 |
MSC:
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05C38 |
MSC:
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05C45 |
MSC:
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05C78 |
idZBL:
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Zbl 1164.05356 |
idMR:
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MR2291739 |
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Date available:
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2009-09-24T11:33:22Z |
Last updated:
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2020-07-03 |
Stable URL:
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http://hdl.handle.net/10338.dmlcz/128069 |
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Reference:
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[1] G. Chartrand and L. Lesniak: Graphs & Digraphs. Third edition.Chapman & Hall, London, 1996. MR 1408678 |
Reference:
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[2] G. Chartrand, L. Nebeský, and P. Zhang: Hamiltonian colorings of graphs.Discrete Appl. Math. 146 (2005), 257–272. MR 2115148, 10.1016/j.dam.2004.08.007 |
Reference:
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[3] G. Chartrand, L. Nebeský, and P. Zhang: On hamiltonian colorings of graphs.Discrete Mathematics 290 (2005), 133–134. MR 2123385, 10.1016/j.disc.2004.10.009 |
Reference:
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[4] G. Chartrand, L. Nebeský, and P. Zhang: Bounds for the hamiltonian chromatic number of a graph.Congressus Numerantium 157 (2002), 113–125. MR 1985129 |
Reference:
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[5] L. Nebeský: Hamiltonian colorings of connected graphs with long cycles.Math. Bohem. 128 (2003), 263–275. MR 2012604 |
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