Normalized Laplacian spectrum of some subdivision-joins and R-joins of two regular graphs

Peer review under responsibility of Kalasalingam University.

Figures & data

Fig. 1 Two cospectral regular graphs.

Fig. 2 Subdivision of $G_1$ and $H_1$.

Fig. 3 Non-regular nonisomorphic $\mathcal{L}$-cospectral graphs $G_1\dot{\vee }{K}_2$ and $H_1\dot{\vee }{K}_2$.