One way to extract information about the structure of a graph is to encode the graph in a matrix and study the invariants of that matrix, such as the spectrum. In this note, we study the spectrum of the Combinatorial Laplacian matrix of a graph. The Combinatorial Laplacian of a simple graphG = (V,E) on the set of n vertices is the n×nmatrix L(G) that records the vertex degrees on its diagonal a...