A spectral approach to bandwidth and separator problems in graphs

Lower bounds on the bandwidth, the size of a vertex separator of general undirected graphs, and the largest common subgraph of two undirected (weighted) graphs are obtained. The bounds are based on a projection technique developed for the quadratic assignment problem, and once more demonstrate the importance of the extreme eigenvalues of the Laplacian. They will be shown to be strict for certain classes of graphs and compare favourably to bounds already known in literature. Further improvement is gained by applying nonlinear optimization methods.

• Type: Conference
• Year: 1993
• Where: IPCO
• Authors: Christoph Helmberg, Bojan Mohar, Svatopluk Poljak, Franz Rendl
• Keywords: General Undirected Graphs, IPCO 1993, IPCO 2007, Largest Common Subgraph, Lower Bounds