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Discussiones Mathematicae Graph Theory 27(1) (2007)
69-82
DOI: https://doi.org/10.7151/dmgt.1345
NONSINGULAR UNICYCLIC MIXED GRAPHS WITH AT MOST THREE EIGENVALUES GREATER THAN TWO
Shi-Cai Gong1,2 and Yi-Zheng Fan1
1School of Mathematics and Computational Science
Anhui University
Hefei, Anhui 230039, P.R. China
2Department of Mathematics and Physics
Anhui University of Science and Technology
Anhui, Huainan 232001
e-mail: fanyz@ahu.edu.cn
e-mail: gongsc@ahuu.edu.cn
Abstract
This paper determines all nonsingular unicyclic mixed graphs on at least nine vertices with at most three Laplacian eigenvalues greater than two.Keywords: unicyclic graph, mixed graph, Laplacian eigenvalue, matching number, spectrum.
2000 Mathematics Subject Classification: 05C50, 15A18.
References
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Received 23 September 2005
Revised 29 November 2006
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