Title:
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Two operations on a graph preserving the (non)existence of 2-factors in its line graph (English) |
Author:
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An, Mingqiang |
Author:
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Lai, Hong-Jian |
Author:
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Li, Hao |
Author:
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Su, Guifu |
Author:
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Tian, Runli |
Author:
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Xiong, Liming |
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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64 |
Issue:
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4 |
Year:
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2014 |
Pages:
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1035-1044 |
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 $G=(V(G),E(G))$ be a graph. Gould and Hynds (1999) showed a well-known characterization of $G$ by its line graph $L(G)$ that has a 2-factor. In this paper, by defining two operations, we present a characterization for a graph $G$ to have a 2-factor in its line graph $L(G).$ A graph $G$ is called $N^{2}$-locally connected if for every vertex $x\in V(G),$ $G[\{y\in V(G)\; 1\leq {\rm dist}_{G}(x,y)\leq 2\}]$ is connected. By applying the new characterization, we prove that every claw-free graph in which every edge lies on a cycle of length at most five and in which every vertex of degree two that lies on a triangle has two $N^{2}$-locally connected adjacent neighbors, has a $2$-factor. This result generalizes the previous results in papers: Li, Liu (1995) and Tian, Xiong, Niu (2012), and is the best possible. (English) |
Keyword:
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2-factor |
Keyword:
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claw-free graph |
Keyword:
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line graph |
Keyword:
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$N^{2}$-locally connected |
MSC:
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05C35 |
MSC:
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05C38 |
MSC:
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05C45 |
idZBL:
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Zbl 06433712 |
idMR:
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MR3304796 |
DOI:
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10.1007/s10587-014-0151-4 |
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Date available:
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2015-02-09T17:38:30Z |
Last updated:
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2020-07-03 |
Stable URL:
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http://hdl.handle.net/10338.dmlcz/144159 |
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Reference:
|
[1] Bondy, J. A., Murty, U. S. R.: Graph Theory with Applications.American Elsevier Publishing Co. New York (1976). MR 0411988 |
Reference:
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Reference:
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[3] Egawa, Y., Ota, K.: Regular factors in $K_{1, n}$-free graphs.J. Graph Theory 15 (1991), 337-344. MR 1111995, 10.1002/jgt.3190150310 |
Reference:
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[4] Gould, R. J., Hynds, E. A.: A note on cycles in 2-factors of line graphs.Bull. Inst. Comb. Appl. 26 (1999), 46-48. Zbl 0922.05046, MR 1683819 |
Reference:
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[5] Li, G., Liu, Z.: On 2-factors in claw-free graphs.Syst. Sci. Math. Sci. 8 (1995), 369-372. Zbl 0851.05084, MR 1374533 |
Reference:
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[6] Ryjáček, Z.: On a closure concept in claw-free graphs.J. Comb. Theory, Ser. B 70 (1997), 217-224. MR 1459867, 10.1006/jctb.1996.1732 |
Reference:
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[7] Ryjáček, Z., Saito, A., Schelp, R. H.: Closure, 2-factors, and cycle coverings in claw-free graphs.J. Graph Theory 32 (1999), 109-117. Zbl 0932.05045, MR 1709653, 10.1002/(SICI)1097-0118(199910)32:2<109::AID-JGT1>3.0.CO;2-O |
Reference:
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[8] Tian, R., Xiong, L., Niu, Z.: On 2-factors in claw-free graphs whose edges are in small cycles.Discrete Math. 312 (2012), 3140-3145. Zbl 1251.05145, MR 2957934, 10.1016/j.disc.2012.07.005 |
Reference:
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[9] Yoshimoto, K.: On the number of components in 2-factors of claw-free graphs.Discrete Math. 307 (2007), 2808-2819. Zbl 1129.05037, MR 2362964, 10.1016/j.disc.2006.11.022 |
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