About:

The International Workshop on Optimal Network Topologies (IWONT) is an established series of workshops for researchers active in the following areas:

• degree-diameter and degree-girth problems in graphs and digraphs;
• construction techniques and structural properties of optimal graphs and digraphs with given properties;
• spectral techniques in graph theory;
• design of networks for optimal efficiency or reliability;
• applications of graphs to theoretical chemistry.

The principal objective of the workshop was to bring together researchers in the relevant areas to consolidate recent advances, present new results and encourage collaborations on extensions of recent work or new ideas. Among the problem areas where we would expect progress reports or further projects to arise from the meeting are the following:

• Existence of Moore graphs; not only the well-known open problem at degree 57 but also mixed graphs, where there are an infinity of open cases and much interest in recent years;
• Upper or lower bounds on the possible defect (in the diameter problem) or excess (in the girth problem) where Moore graphs are known not to exist;
• Restricted problems, such as optimal Cayley graphs or vertex-transitive graphs, bipartite graphs, graphs embeddable on surfaces of given genus and so on;
• Analogues of the girth problem on undirected graphs, such as extensions to digraphs, mixed graphs and hypergraphs and related concepts such as geodecity.