3 papers
math.CO2026
Directed strongly regular graphs and divisible design graphs from Tatra association schemes
Mikhail Muzychuk, Grigory Ryabov
In this paper, we construct directed strongly regular graphs and divisible design graphs with new parameters merging some basic relations of so-called Tatra associations schemes. W…
math.CO2024
On a family of divisible design digraphs
Mikhail Muzychuk, Grigory Ryabov
For every odd prime power , a family of pairwise nonisomorphic normal arc-transitive divisible design Cayley digraphs with isomorphic neighborhood designs over a Heisenberg grou…
math.CO2023
Constructing linked systems of relative difference sets via Schur rings
Mikhail Muzychuk, Grigory Ryabov
In the present paper, we study relative difference sets (RDSs) and linked systems of them. It is shown that a closed linked system of RDSs is always graded by a group. Based on thi…