Báo cáo khoa học:Voltage Graphs, Group Presentations and Cages

The cage problem asks for the construction of regular graphs with specified degree and girth. Reviewing terminology, we recall that the girth of a graph is the length of a shortest cycle, that a (k, g)-graph is regular graph of degree k and girth g, and that a (k, g)-cage is a (k, g)-graph of minimum possible order. Define f(k, g) to be this minimum. We focus on trivalent (or cubic) cages. It is well known that...