Some non-sign-symmetric signed graphs with symmetric spectrum

2019/09/15 by Ramezani, Farzaneh
#Combinatorics (math.CO) #FOS: Mathematics

paper · doi:10.48550/arxiv.1909.06821

Abstract

We construct infinitely many signed graphs having symmetric spectrum, by using the NEPS and rooted product of signed graphs. We also present a method for constructing large cospectral signed graphs. Although the obtained family contains only a minority of signed graphs, it strengthen the belief that the signed graphs with symmetric spectrum are deeper than bipartite graphs, i.e the unsigned graphs with symmetric spectrum.

Related

• The signed graphs with symmetric spectra
• On sign-symmetric signed graphs
• Cospectrality results for signed graphs with two eigenvalues unequal to ± 1
• On adjacency and Laplacian cospectral non-isomorphic signed graphs
• Signed (0,2)-graphs with few eigenvalues and a symmetric spectrum