Title:
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On detectable colorings of graphs (English) |
Author:
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Escuadro, Henry |
Author:
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Zhang, Ping |
Language:
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English |
Journal:
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Mathematica Bohemica |
ISSN:
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0862-7959 (print) |
ISSN:
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2464-7136 (online) |
Volume:
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130 |
Issue:
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4 |
Year:
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2005 |
Pages:
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427-445 |
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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Let $G$ be a connected graph of order $n \ge 3$ and let $c\: E(G) \rightarrow \lbrace 1, 2, \ldots , k\rbrace $ be a coloring of the edges of $G$ (where adjacent edges may be colored the same). For each vertex $v$ of $G$, the color code of $v$ with respect to $c$ is the $k$-tuple $c(v) = (a_1, a_2, \cdots , a_k)$, where $a_i$ is the number of edges incident with $v$ that are colored $i$ ($1 \le i \le k$). The coloring $c$ is detectable if distinct vertices have distinct color codes. The detection number $\det (G)$ of $G$ is the minimum positive integer $k$ for which $G$ has a detectable $k$-coloring. We establish a formula for the detection number of a path in terms of its order. For each integer $n \ge 3$, let $D_u(n)$ be the maximum detection number among all unicyclic graphs of order $n$ and $d_u(n)$ the minimum detection number among all unicyclic graphs of order $n$. The numbers $D_u(n)$ and $d_u(n)$ are determined for all integers $n \ge 3$. Furthermore, it is shown that for integers $k \ge 2$ and $n \ge 3$, there exists a unicyclic graph $G$ of order $n$ having $\det (G)=k$ if and only if $d_u(n) \le k \le D_u(n)$. (English) |
Keyword:
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detectable coloring |
Keyword:
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detection number |
Keyword:
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unicyclic graph |
MSC:
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05C15 |
MSC:
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05C70 |
idZBL:
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Zbl 1111.05034 |
idMR:
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MR2182387 |
DOI:
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10.21136/MB.2005.134214 |
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Date available:
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2009-09-24T22:23:06Z |
Last updated:
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2020-07-29 |
Stable URL:
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http://hdl.handle.net/10338.dmlcz/134214 |
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Reference:
|
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Reference:
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[2] M. Aigner, E. Triesch, Z. Tuza: Irregular assignments and vertex-distinguishing edge-colorings of graphs.Combinatorics ’90, Proc. Conf., Gaeta/Italy 1990, Elsevier Science Pub., New York (1992), 1–9. MR 1195794 |
Reference:
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[3] A. C. Burris: On graphs with irregular coloring number $2$.Congr. Numerantium 100 (1994), 129–140. Zbl 0836.05029, MR 1382313 |
Reference:
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[4] A. C. Burris: The irregular coloring number of a tree.Discrete Math. 141 (1995), 279–283. Zbl 0829.05027, MR 1336691, 10.1016/0012-365X(93)E0225-S |
Reference:
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[5] G. Chartrand, H. Escuadro, F. Okamoto, P. Zhang: Detectable colorings of graphs.(to appear). MR 2212794 |
Reference:
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[6] G. Chartrand, P. Zhang: Introduction to Graph Theory.McGraw-Hill, Boston, 2005. |
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