Date of Award
Doctor of Philosophy
We present an infinite example of trees cospectral with respect to the normalized Laplacian and a use of the weighted normalized Laplacian to find cospectral pairs of unweighted bipartite graphs with respect to the normalized Laplacian. We show that almost all trees are cospectral with respect to the normalized Laplacian. Further, we show that almost all trees are cospectral with respect to the generalized characteristic polynomial. This would imply that almost all trees T have a mate T' such that T and T' are simultaneously cospectral with respect to all of the adjacency, (signless) Laplacian, and normalized Laplacian matrices.
Osborne, Steven, "Cospectral bipartite graphs for the normalized Laplacian" (2013). Graduate Theses and Dissertations. 13544.