Lethbridge Number Theory and Combinatorics Seminar: Mikhail Muzychuk

An association scheme is a coloring of a complete graph satisfying certain regularity conditions. It is a generalization of groups and has many applications in algebraic combinatorics. Every association scheme yields a special matrix algebra called the Bose-Mesner algebra of a scheme. A scheme is called commutative if its Bose-Mesner algebra is commutative. Commutative schemes were the main topic of the research in this area for decades. Only recently non-commutative association schemes attracted the attention of researchers. In my talk I'll present the results about non-commutative association schemes of the smallest possible rank, rank 6. This is a joint work with A.Herman and B.Xu.