Abstract

Graphs $G$ and $H$ are called cospectral if they have the same characteristic polynomial, equivalently, if they have the same eigenvalues considering multiplicities. In this article we introduce a construction to produce pairs of cospectral regular graphs. We also investigate conditions under which the graphs are integral.

Keywords: Eigenvalue; cospectral graphs; adjacency matrix; integral graphs

MSC: 05C50

Pages:  66$-$76     

Volume  68 ,  Issue  1 ,  2016