演讲者:冯荣权(北京大学)
时间:2018-04-02 10:00-11:00
地点:慧园3栋 415报告厅
An (n, k, t, λ, µ)-directed strongly regular graph is a directed graph with n vertices satisfying (i) each vertex has k out-neighbors and k in-neighbors, including t neighbors counted as both in- and out-neighbors of the vertex; and (ii) the number of paths of length two from a vertex x to another vertex y is λ if there is a directed edge from x to y, and is µ otherwise. Such graphs were introduced by Duval in 1988 as one of the possible generalization of classical strongly regular graphs to the directed case. Cayley graphs on dihedral groups are called dihedrants. In this talk, several constructions of directed strongly regular dihedrants will be given and two special directed strongly regular dihedrants will be characterized.