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.
Keywords:
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.