Modular Terwilliger algebras of association schemes
arXiv:2004.09692 · doi:10.1007/s00373-021-02363-0
Abstract
We define modular Terwilliger algebras of association schemes, Terwilliger algebras over a positive characteristic field, and consider basic properties. We give a condition for the modular Terwilliger algebra to be non-semisimple. We show that the dimension of a Terwilliger algebra of a Johnson scheme depends on the characteristic of the coefficient field. We also give some other examples.