that does the mathematics and that draws accurate graphs from which students can see the key results. He backs up this no … of other economics courses in using graphs to illustrate the results, and draw the graphs accurately, then they can teach …

We study the connected regular graphs with four distinct eigenvalues. Properties and feasibility conditions of the …

equally large sets at maximal distance are given, and we find graphs for which the bounds are tight. …

We give several old and some new applications of eigenvalue interlacing to matrices associated to graphs. Bounds are … obtained for characteristic numbers of graphs, such as the size of a maximal (co)clique, the chromatic number, the diameter and … inequalities and regularity results concerning the structure of graphs and block designs. …

We characterize the distance-regular graphs with diameter three by giving an expression for the number of vertices at …

given and characterized. A list of feasible parameter sets for graphs with at most 40 vertices is generated. …