Abstract
A signed graph consists of an underlying graph and a sign function , which assigns each edge of a sign, either positive or negative. The adjacency matrix of a signed graph is defined as with , where is the adjacency matrix of the underlying graph . The rank of is defined to be the rank of . In this paper, we characterize the signed graphs with rank or , and characterize the signed planar graphs with rank 4.
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Acknowledgements
The authors thank the referees for a careful and thorough reading of the paper and for valuable comments.
Notes
No potential conflict of interest was reported by the authors.