ON NEW CLASSES OF MULTICONE GRAPHS DETERMINED BY THEIR SPECTRUMS

A multicone graph is defined to be join of a clique and a regular graph. A graph G is cospectral with graph H if their adjacency matrices have the same eigenvalues. A graph G is said to be determined by its spectrum or DS for short, if for any graph H with Spec(G)=Spec(H), we conclude that G is isomorphic to H. In this paper, we present new classes of multicone graphs that are DS with respect to their spectrums. Also, we show that complement of these graphs are DS with respect to their adjacency spectrums. In addition, we show that graphs cospectral with these graphs are perfect. Finally, we find automorphism group of these graphs and one conjecture for further researches is proposed.