Directed Strongly Regular Dihedrants

Speaker: Professor Rongquan Feng,  Peking University, Beijing

Time: 11:30-13:30， March 29, Friday, 2019

Venue: 200-9, Sir Run Run Shaw Business Building

Abstract:   An (n; k; t; lambda, mu )-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 lambda  if there is a directed edge from x to y, and is mu 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.