Linked systems of relative difference sets
主 讲 人 ：Grigory Ryabov 副教授
活动时间：09月25日15时00分
地 点 ：理科群1号楼D203室
讲座内容：
The talk is concerned with linked systems of relative difference sets (RDSs for short) which are special case of linked systems of symmetric group divisible designs whose notion goes back to the papers of Cameron and Higman. These objects have close connections to association schemes, coding theory, and other parts of combinatorics.
In the talk, we show that a closed linked system of RDSs is always graded by a group. Based on this result, we also define a product of RDS linked systems sharing the same grading group. Further, we generalize some known constructions of linked systems of RDSs and construct new linked system of RDSs in a Heisenberg group over a finite field. Finally, we present a new infinite family of pairwise nonisomorphic divisible design Cayley digraphs constructed from a linked system of RDSs.
The talk is based on joint work with M. Muzychuk.
主讲人介绍：
Grigory Ryabov has obtained a PhD degree at Sobolev Institute of Mathematics and Novosibirsk State University in 2019. He was working at Sobolev Institute of Mathematics (research assistance, research fellow, senior research fellow, 2016-2023), St. Petersburg Department of Steklov Mathematical Institute (postdoctoral research fellow, 2021-2022), Ben-Gurion University of the Negev (postdoctoral research fellow, 2023-2024). Now he is an associate professor at Novosibirsk State Technical University. The main research interests are in the algebraic combinatorics, namely, in Cayley graphs, coherent configurations, permutations groups. He published 25 papers in scientific journals.
