The Subconstituent Algebra of an Association Scheme (Part III)

This is the continuation of an article from the previous issue. In this part, we focus on the thin P- and Q-polynomial association schemes. We provide some combinatorial characterizations of these objects and exhibit the known examples with diameter at least 6. For each example, we give the irreducible modules for the subconstituent algebra. We close with some conjectures and open problems.