Seminar in Discrete Mathematics - Sergey Goryainov

This week's seminar is given by Sergey Goryainov, Hebei Normal University.

Title: Divisible design graphs from the symplectic graph Sp(4, q)

Abstact: For any odd prime power q, we construct a new divisible design graph that is based on the symplectic graph Sp(4, q). We also show that the complement of Sp(4, q) admits three special kinds of equitable partitions. This gives rise to three more infinite families of divisible design graphs. The smallest graphs in these four families have 40 vertices.

Joint work with Bart De Bruyn, Willem Haemers and Leonid Shalaginov.