Czechoslovak Mathematical Journal, Vol. 68, No. 4, pp. 1105-1114, 2018


Even factor of bridgeless graphs containing two specified edges

Nastaran Haghparast, Dariush Kiani

Received March 13, 2017.   Published online May 14, 2018.

Abstract:  An even factor of a graph is a spanning subgraph in which each vertex has a positive even degree. Let $G$ be a bridgeless simple graph with minimum degree at least $3$. Jackson and Yoshimoto (2007) showed that $G$ has an even factor containing two arbitrary prescribed edges. They also proved that $G$ has an even factor in which each component has order at least four. Moreover, Xiong, Lu and Han (2009) showed that for each pair of edges $e_1$ and $e_2$ of $G$, there is an even factor containing $e_1$ and $e_2$ in which each component containing neither $e_1$ nor $e_2$ has order at least four. In this paper we improve this result and prove that $G$ has an even factor containing $e_1$ and $e_2$ such that each component has order at least four.
Keywords:  bridgeless graph; components of an even factor; specified edge
Classification MSC:  05C70


References:
[1] J. A. Bondy, U. S. R. Murty: Graph Theory with Applications. American Elsevier Publishing, New York (1976). DOI 10.1007/978-1-349-03521-2 | MR 0411988 | Zbl 1226.05083
[2] B. Jackson, K. Yoshimoto: Even subgraphs of bridgeless graphs and 2-factors of line graphs. Discrete Math. 307 (2007), 2775-2785. DOI 10.1016/j.disc.2006.11.023 | MR 2362962 | Zbl 1127.05080
[3] B. Jackson, K. Yoshimoto: Spanning even subgraphs of 3-edge-connected graphs. J. Graph Theory 62 (2009), 37-47. DOI 10.1002/jgt.20386 | MR 2547846 | Zbl 1180.05057
[4] T. A. McKee: Recharacterizing Eulerian: Intimations of new duality. Discrete Math. 51 (1984), 237-242. DOI 10.1016/0012-365X(84)90004-9 | MR 0762316 | Zbl 0547.05043
[5] L. Xiong, M. Lu, L. Han: The structure of even factors in claw-free graphs. Discrete Math. 309 (2009), 2417-2423. DOI 10.1016/j.disc.2008.05.020 | MR 2509009 | Zbl 1214.05139

Affiliations:   Nastaran Haghparast, Dariush Kiani (corresponding author), Department of Mathematics and Computer Sciences, Amirkabir University of Technology, Tehran, Iran, e-mail: nhaghparast@aut.ac.ir, dkiani@aut.ac.ir


 
PDF available at: