Alan J. Hoffman, The Change in the Least Eigenvalue of the Adjacency Matrix of a Graph Under Imbedding, SIAM Journal on Applied Mathematics, Vol. 17, No. 4 (Jul., 1969), pp. 664-671 ...

Some recent work in the mathematical physics literature has shown that the exponential of a network's adjacency matrix can be used as the basis for defining and computing specific versions of these ...